collapse - a mishap caused by something suddenly falling down or caving in

gravitational collapse - the implosion of a star resulting from its own gravity; the result is a smaller and denser celestial object

blockage, occlusion, closure - the act of blocking

occlusive, plosive, plosive consonant, plosive speech sound, stop consonant, stop - a consonant produced by stopping the flow of air at some point and suddenly releasing it; "his stop consonants are too aspirated"