Synonyms and related words :
bomb, break, cave in, collapse, come apart, come unstuck, conk out, crumble, decline, disintegrate, droop, drop, fade, fail, faint, fall flat, fizzle out, flag, give out, give way, go downhill, go soft, go to pieces, hit the skids, languish, peg out, peter out, pine, poop out, sink, weaken, wear away, wilt, yield