IPA: /ˈkrʌmbliər/
KK: /ˈkrʌmbliər/
More likely to break into small pieces or crumbs than something else.
The crumblier the cake, the more difficult it is to slice neatly.
Crumblier → It is formed from "crumble" (from Old English "cromblian", meaning to break into small pieces) and the comparative suffix "-ier" (meaning more). The word "crumblier" means more likely to break into small pieces.
Think of something that is 'more likely to break into small pieces' — that's what crumblier means.