buddy
bud·dy
I
 /ˈbʌdi/  noun  ,  pl   -dies
  1 [  count  ] informal : a close friend
  — used especially to describe men or boys who are friends
   We've been buddies [=pals, (chiefly Brit) mates] since junior high school.
   He's one of my old army buddies.
   a buddy from college = a college buddy
  2 [  singular  ] US, informal + sometimes impolite
  — used to address a man who you do not know
   Hey, buddy, do you know where Maple Street is?
  3 [  count  ] : a person who does some activity with you
   His fishing buddy just bought a new boat.
   her drinking buddies [=the people who often drink alcohol with her]
  the buddy system
    US   : an arrangement in which two people help or protect each other
    If your children walk to school, have them use the buddy system. [=have them walk with other children]
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II
  verb  , buddies, bud·died, bud·dy·ing
  buddy up [  phrasal verb  ]
     US    informal   : to become friendly especially in order to get help or some advantage
    — often + with
    New students are encouraged to buddy up with older students.
   
    — often + to
    businessmen buddying up to [=cozying up to] politicians to get their support
   
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III
  adj  , always used before a noun
   informal   : telling a story about a friendship between two usually male characters
   a buddy movie/comedy