Wordnet 3.0
VERB (1)
1. 
 swing from one hold to the next; 
- Example: "the monkeys brachiate"ADJECTIVE (2)
1. 
 having widely spreading paired branches; 
- Example: "maples are brachiate"2. 
 having arms or armlike appendages; 
The Collaborative International Dictionary of English v.0.48:
Brachiate \Brach"i*ate\, a. [L. brachiatus (bracch-) with boughs
   or branches like arms, from brackium (bracch-) arm.] (Bot.)
   Having branches in pairs, decussated, all nearly horizontal,
   and each pair at right angles with the next, as in the maple
   and lilac.
   [1913 Webster]
WordNet (r) 3.0 (2006):
brachiate
    adj 1: having widely spreading paired branches; "maples are
           brachiate"
    2: having arms or armlike appendages
    v 1: swing from one hold to the next; "the monkeys brachiate"