#1
crack v. [
check, break] become fractured; break or crack on the surface only; "The glass cracked when it was heated"
. wn #2
crack v. make a very sharp explosive sound; "His gun cracked"
. wn #3
crack n. [
cleft, crevice, fissure, scissure] a long narrow opening
. wn #4
crack s. [
ace, A-one, first-rate, super, tiptop, topnotch, top-notch, tops] of the highest quality; "an ace reporter"; "a crack shot"; "a first-rate golfer"; "a super party"; "played top-notch tennis"; "an athlete in tiptop condition"; "she is absolutely tops"
. wn #5
crack n. [
gap] a narrow opening; "he opened the window a crack"
. wn