'pin down' definitions:

Definition of 'pin down'

(from WordNet)
verb
Define clearly; "I cannot narrow down the rules for this game" [syn: pin down, peg down, nail down, narrow down, narrow, specify]
verb
Place in a confining or embarrassing position; "He was trapped in a difficult situation" [syn: trap, pin down]
verb
Attach with or as if with a pin; "pin up a picture" [syn: pin down, pin up]