[syn: chummy, buddy-buddy, thick(p)]
The Collaborative International Dictionary of English v.0.48:
chummy \chummy\ adj.
   1. having the relationship of friends or pals. [colloquial]
   Syn: matey, pally, palsy-walsy.
        [WordNet 1.5]
   2. associated on close terms. [informal]
   Syn: thick(predicate).
        [WordNet 1.5]
WordNet (r) 3.0 (2006):
chummy
    adj 1: (used colloquially) having the relationship of friends or
           pals [syn: chummy, matey, pally, palsy-walsy]
    2: (used informally) associated on close terms; "a close
       friend"; "the bartender was chummy with the regular
       customers"; "the two were thick as thieves for months" [syn:
       chummy, buddy-buddy, thick(p)]