'nail down' definitions:

Definition of 'nail down'

From: WordNet
verb
Succeed in obtaining a position; "He nailed down a spot at Harvard" [syn: nail down, nail, peg]
verb
Define clearly; "I cannot narrow down the rules for this game" [syn: pin down, peg down, nail down, narrow down, narrow, specify]
verb
Make final; put the last touches on; put into final form; "let's finalize the proposal" [syn: finalize, finalise, settle, nail down]

Synonyms of 'nail down'

From: Moby Thesaurus