WordNet (r) 3.0 (2006):
pin down v 1: define clearly; "I cannot narrow down the rules for this game" [syn: pin down, peg down, nail down, narrow down, narrow, specify] 2: place in a confining or embarrassing position; "He was trapped in a difficult situation" [syn: trap, pin down] 3: attach with or as if with a pin; "pin up a picture" [syn: pin down, pin up]