brush
I
 /ˈbrʌʃ/  noun  ,  pl   brush·es [  count  ]
  1 : a tool with many stiff hairs, fibers, etc., that is used for cleaning, smoothing, or painting something
   Use a wire brush to get the rust off the metal.
  — see also hairbrush, paintbrush, toothbrush
  2 a : an act of cleaning or smoothing something with a brush
   I gave my daughter's hair a quick brush.
  2 b : a quick, light movement
   She wiped the crumbs off the table with a brush of her hand.
  (as) daft as a brush — see daft
  tar (someone) with the same brush — see tar, 2
 — compare brush, 3, brush, 4
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II
  verb  , brushes, brushed, brush·ing [  + obj  ]
  1 a : to clean or smooth (something) with a brush
   brush your teeth/hair
  1 b : to put (something) on or onto something with a brush
   Brush some butter onto the fish before cooking it.
  2 : to remove (something) with a brush or with a quick movement of your hand, fingers, etc.
   Brush the dirt off your pants.
   The camera showed him brushing [=wiping] away a tear.
  3 : to touch gently against (something) when going past it
   Leaves brushed my cheek.
   The two men brushed shoulders [=touched at the shoulders] as they walked past each other.
  4 : to move quickly past someone without stopping or paying attention
   The governor brushed by/past the reporters.
  brush aside [  phrasal verb  ]
   brush (something) aside or brush aside (something) : to treat (something) as not important : to ignore or dismiss (something)
    He brushed aside [=brushed off] questions about his son's arrest.
  brush off [  phrasal verb  ]
   1 brush (something) off or brush off (something) : to treat (something) as not important : to refuse to deal with or talk about (something) in a serious way
    The company brushed off [=brushed aside] reports that it couldn't pay its bills.
   2 brush (someone) off or brush off (someone) : to respond to (someone) in a rude way that shows you are not interested in what is being asked for or suggested
    I asked him for some help, but he just brushed me off.
    — see also brush-off
  brush up [  phrasal verb  ]
   brush up or brush up (something) : to improve your skill at (something) or increase your knowledge of (something)
    My Spanish is very rusty. I need to brush up before I go on my vacation to Mexico.
    I need to brush up my Spanish.
    — often + on
    I need to brush up on my Spanish.
   
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III
  noun  ,  pl   brushes [  count  ]
  : a situation in which you briefly experience or almost experience something bad, dangerous, exciting, etc.
  — + with
   As a teenager he had several brushes with the law. [=was in trouble with police several times]
   She had a brush with [=briefly saw or met] a famous actor at a restaurant in New York.
   Her brush with fame/greatness came when she sang the national anthem at the football game.
   He had a brush with death [=he almost died] when climbing the mountain.
 — compare brush, 1, brush, 4
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IV
  noun   [  noncount  ]
  1 : wood from small branches on a tree
   a pile of brush
  2 : small bushes or trees
   a hillside covered with dense brush
   a lion hiding in the brush
  — see also underbrush
 — compare brush, 1, brush, 3