The Collaborative International Dictionary of English v.0.48:
Billiard \Bil"liard\, a. Of or pertaining to the game of billiards. "Smooth as is a billiard ball." --B. Jonson. [1913 Webster]WordNet (r) 3.0 (2006):
billiard adj 1: of or relating to billiards; "a billiard ball"; "a billiard cue"; "a billiard table"