knock
I
 /ˈnɑːk/  verb  , knocks, knocked, knock·ing
  1 [  no obj  ] : to hit something (such as a door) with the knuckles of your hand or with a hard object (such as a knocker) in order to get people's attention
   I heard someone knocking (at the door).
  — usually + on
   I knocked on the door but no one answered.
   He knocked on the table to call the meeting to order.
   Campaign workers have been knocking on doors throughout the neighborhood. [=have been going to each house or apartment in the neighborhood to talk with the people who live there]
  — sometimes used figuratively
   a talented young singer who is knocking on the door of success [=who is very close to achieving success]
  2 always followed by an adverb, adjective, or preposition [  + obj  ] : to hit (something or someone) in a forceful way
   The ball knocked him on the chin.
   knock one stick against another = knock two sticks together
   She knocked the glass from his hand.
   He knocked the baseball over the fence.
   The ball hit him in the mouth and knocked out one of his teeth.
   The wind knocked him backwards.
   The wind almost knocked him off his feet. = The wind almost knocked him to the ground. [=the wind hit him so hard that he almost fell to the ground]
   The collision knocked him unconscious/senseless. [=caused him to become unconscious]
   The collision knocked him flying. [=sent him flying through the air]
  3 always followed by an adverb or preposition : to touch or hit someone or something in a way that is not planned or intended
   [  no obj  ] The dog knocked against the lamp.
    My knee accidentally knocked against the table.
    Skaters were knocking into each other all over the ice.
    I kept knocking against him during the bumpy ride. = He and I kept knocking together during the bumpy ride.
   [  + obj  ] I accidentally knocked my knee against the table.
  4 [  + obj  ] : to make (something, such as a hole) by hitting something
   He used a hammer to knock a hole in the wall.
  5 [  + obj  ] informal : to criticize (someone or something)
   He's always knocking the government.
   Don't knock it until you've tried it. [=wait until you try something before criticizing it]
  6 [  no obj  ] : to produce a repeated loud noise
   The engine was knocking.
   The pipes were knocking.
  heart is knocking
    informal  
   ◇ If your heart is knocking it is beating very hard, usually because you are nervous or excited.
    His heart was knocking in his chest.
   
  knees are knocking
    informal  
   ◇ If your knees are knocking they are shaking because you are nervous or afraid.
    Her knees were knocking in terror.
   
  knock around ( also Brit   knock about) [  phrasal verb  ]
     informal  
   1 a knock around/about (a place) or knock around/about : to spend time in (a place) without having a goal or purpose : to wander around (a place)
    He spent the summer knocking around (in) Europe.
   1 b knock around/about with (someone) Brit : to spend time with (another person)
    She was knocking around [=hanging around] with her brother.
   2 a : to be considered or discussed in an informal way over a period of time
    These ideas have been knocking around [=kicking around] for years.
   2 b knock around (something) or knock (something) around : to consider or talk about (ideas, plans, etc.) in an informal way
    We knocked the plan around for a while before we came to an agreement.
    They knocked around several possible names for the new car.
   3 knock (someone) around/about : to beat or hit (someone) badly or repeatedly
    The boy was getting knocked around by bullies.
    — often used figuratively
    I really got knocked around at the last staff meeting.
   
   4 chiefly Brit : to be lying somewhere within a general area or place
    That jacket is knocking about/around here somewhere.
  knock back
    informal  
   1 knock (something) back or knock back (something) : to drink or swallow (an alcoholic drink) quickly
    He stopped at a bar after work to knock back a few beers.
   2 knock (someone) back : to cost (someone) a lot of money
    That car must have knocked you back quite a bit. [=you must have spent a lot of money on that car]
  knock down [  phrasal verb  ]
   1 knock (someone or something) down or knock down (someone or something)
   1 a : to cause (someone or something) to fall to the ground
    He hit him on the chin and knocked him down.
    The storm knocked down [=knocked over] several big trees.
    Rowdy fans knocked down the fence.
    We're planning to knock down [=remove, demolish] a wall to create a bigger room.
   1 b Brit : to hit and injure or kill (a person or animal) with a vehicle
    She was knocked down [=(Brit) knocked over, (US) hit] by a car while crossing the street.
   2 informal
   2 a knock (something) down or knock down (something) : to reduce or lower (a price, an amount, etc.)
    They knocked down the price of the house by 10 percent.
    He wanted $50 for it but I managed to knock the price down to $45.
   2 b knock (someone) down : to cause or persuade (someone) to reduce a price
    He wanted $50 for it but I managed to knock him down to $45.
   3 knock down (an amount of money) US, informal : to receive (an amount of money) as income or salary
    He knocks down almost a million dollars a year.
   4 knock down (a shot) or knock (a shot) down basketball : to succeed in making (a shot) especially from a long distance
    He was knocking down jump shots.
   5 knock (something) down or knock down (something) chiefly US, informal : to say no to (an idea, plan, proposal, etc.) : reject
    His boss knocked down [=shot down] all of his ideas.
   6 knock (something) down or knock down (something) US : to take (something) apart
    We knocked the bed down so it would fit in the truck.
  knock heads
    US    informal  
   1 : to argue or disagree
    The two of them knocked heads soon after they started working together.
   2 : to use angry or forceful methods to control or punish people
    I am going in there and knock some heads if they don't start behaving.
    — often + together
    I am going to go in there and knock their heads together if they don't start behaving.
   
  knock in [  phrasal verb  ]
   knock (a run or runner) in or knock in (a run or runner) baseball : to cause (a run or runner) to score
    He knocked in [=batted in, drove in] a run in the second inning with a double to left field.
  knock off [  phrasal verb  ]
     informal  
   1 knock off or knock (something) off or knock off (something) : to stop doing something (such as work)
    We are going to knock off for lunch in 10 minutes.
    The boss said we could knock off early today. = The boss said we could knock off work early today.
    — often used as a command to tell someone to stop doing something immediately
    Knock off your fighting right now!
    I told you two kids to knock it off!
   
   2 knock (something) off or knock off (something)
   2 a : to do or make (something) very quickly
    He knocked off 10 paintings in 4 days.
    We are planning to knock this project off in a weekend.
   2 b : to take (an amount) away from something
    He agreed to knock off 10 dollars from the price. [=to reduce the price by 10 dollars]
    This shortcut will knock at least 100 miles off the journey.
   2 c US : to steal money or things from (a bank or store)
    They knocked off [=knocked over] a jewelry store.
   2 d chiefly Brit : to steal (something)
    They knocked off a lot of valuable merchandise.
   2 e US : to make a cheaper copy of (something)
    Several other companies knocked off their dress design.
    — see also knockoff
   3 knock (someone) off or knock off (someone)
   3 a : to kill (someone)
    He tried to knock off two men who owed him money.
    Did she really want to knock her husband off?
   3 b US : to defeat (someone)
    They knocked off the best team in the league.
  knock on wood — see wood, 1
  knock out [  phrasal verb  ]
   1 knock (someone or something) out or knock out (someone or something)
   1 a : to make (a person or animal) unconscious
    The drug knocked him out.
    The force of the collision knocked him out. [=knocked him cold]
    He hit his head against the table when he fell and knocked himself out.
   1 b boxing : to defeat (an opponent) with a punch that knocks the opponent down for a certain amount of time
    He was knocked out in the third round.
    — see also knockout 1, 1
   1 c : to defeat (an opponent) in a competition so that the opponent cannot continue
    My team was the favorite to win the championship, but we were knocked out (of the competition) in the third round.
   1 d baseball : to cause (a pitcher) to be removed from the game by getting many hits
    The starting pitcher was knocked out (of the game) in the fourth inning.
   2 knock (something) out or knock out (something)
   2 a : to cause (something) to stop working
    Missiles knocked out the television station.
    The storm knocked out electricity across the state.
   2 b : to produce (something) very quickly
    a musical group that just keeps knocking out hit records
   3 knock (yourself) out informal
   3 a : to make (yourself) very tired by doing work
    They knocked themselves out trying to build a garage.
    I knocked myself out [=I worked very hard] to get the job done on time.
   3 b US
    — used to tell someone to go ahead and do something
    “Do you mind if I use this exercise machine first?” “Knock yourself out.”
   
   4 knock (someone) out informal : to make a very strong and good impression on (someone)
    Her beauty just knocks me out. [=I think she is very beautiful]
    Everyone was knocked out by his suggestion. [=everyone liked his suggestion very much]
    — see also knockout 2, 1
  knock over [  phrasal verb  ]
   1 knock (someone or something) over or knock over (someone or something)
   1 a : to cause (someone or something) to fall to the ground
    The dog knocked over the lamp.
    The wind was so strong that it almost knocked her over. [=knocked her down]
   1 b Brit : to hit and injure or kill (a person or animal) with a vehicle
    The dog was knocked over [=(Brit) knocked down, (US) hit] by a car.
   2 knock (someone) over or knock over (someone) informal : to greatly surprise or shock (someone)
    He was knocked over [=overwhelmed] by the news.
    When I found out I had won, you could have knocked me over with a feather. [=I was extremely surprised or astonished]
   3 knock (something) over or knock over (something) US, informal
   3 a : to steal money or things from (a bank or store)
    Three men knocked over [=knocked off] a bank.
   3 b : to steal (something)
    They knocked over a truckload of goods.
  knock (someone) cold
   : to cause (someone) to become unconscious
    He knocked his opponent cold with one punch.
    She was knocked cold [=knocked out] by the collision.
  knock (someone) dead
    informal   : to make a very strong and good impression on (someone)
    Her performance really knocked the audience dead. [=the audience greatly enjoyed her performance]
    She told him to go out there on the stage and knock 'em dead.
  knock (someone) for a loop — see loop, 1
  knock (someone) for six — see six
  knock someone's head/block off
    informal   : to hit someone very hard
    I'm so angry I'd like to knock his block off.
  knock (someone) sideways
    Brit   : to upset, confuse, or shock (someone) very much
    The news about his mother's accident really knocked him sideways.
  knock some sense into — see sense, 1
  knock (something) on the head
    Brit    informal   : to cause the end or failure of (something)
    The closing of the airport knocked our holiday plans on the head.
  knock spots off — see spot, 1
  knock the (living) daylights out of — see daylight
  knock the stuffing out of — see stuffing
  knock together [  phrasal verb  ]
   knock (something) together or knock together (something) : to make or build (something) in a quick or careless way
    a rough table that was knocked together from old pieces of wood
  knock up [  phrasal verb  ]
   1 knock (someone) up or knock up (someone) informal
   1 a chiefly US, impolite : to make (someone) pregnant
    She got knocked up. [=she got pregnant]
   1 b Brit : to wake (someone) by knocking on a door
    knocked him up at 6 a.m.
   2 knock (something) up or knock up (something) Brit : to make or produce (something) quickly
    knock up a quick meal
  knock your socks off — see sock, 1
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II
  noun  ,  pl   knocks
  1 [  count  ]
  1 a : a hard, sharp hit
   He gave him a knock on the head.
  1 b : the sound made by a hard hit
   There was a loud knock at the door.
  2 [  count  ] informal : an experience that makes you less confident or successful for a period of time : a difficult or painful experience
   She took some knocks early in her career.
   Most performers have their share of knocks [=setbacks] on their way to stardom.
  — see also HARD KNOCKS ((BELOW))
  3 [  count  ] informal : a critical or negative comment
   He likes praise but can't stand the knocks.
  — often used in U.S. English in the phrase the knock against
   The knock against her is that she can't win the important matches. [=people say that she cannot win the important matches]
   One of the knocks against television is that there are too many commercials.
  4 : a loud noise produced by an engine when it is not working properly
   [  count  ] We heard a knock in the engine.
   [  noncount  ] a type of fuel that reduces engine knock
  hard knocks
   : difficult or painful experiences that people have in their lives or careers
    He has taken plenty of hard knocks in his life.
    The school of hard knocks [=the difficult experiences in his life] taught him how to be tough.