#1
crumble v. [
crumple, tumble, break down, collapse] fall apart; "the building crumbled after the explosion"; "Negotiations broke down"
. wn #2
crumble v. [
fall apart] break or fall apart into fragments; "The cookies crumbled"; "The Sphinx is crumbling"
. wn #3
crumble v. [
decay, dilapidate] fall into decay or ruin; "The unoccupied house started to decay"
. wn