Synonyms to be disappointing

fall short, be found wanting, be inferior, be insufficient, collapse, come short, crash, decline, fail, fail of, fall, fall away, fall dead, fall down, fall flat, fall in, fall shy, fall stillborn, fall through, fizzle, fizzle out, follow, go to smash, go wrong, have nothing on, kick the beam, lack, lag, lose ground, miss, miss out, miss the mark, not answer, not approach, not bear inspection, not come near, not compare, not hack it, not make it, not make out, not measure up, not pass muster, not qualify, not stretch, not suffice, peter out, play second fiddle, rank under, run short, serve, slump, stop short, subserve, turn sour, want, be unproductive, blow up, break, break down, burn out, cave in, come apart, come to naught, come to nothing, come unstuck, conk out, crumble, die, die away, die out, disintegrate, droop, drop, explode, fade, fail miserably, faint, fizz out, flag, flame out, get bogged down, get hung up, get mired, get nowhere, give out, give way, go do