flimsy

1 being of a material lacking in sturdiness or substance a flimsy scarf that was more for decoration than for warmth Synonyms cobwebby, filmy, frothy, gauzy, gossamer, gossamery, insubstantial, sleazy, unsubstantial Related Words dainty, delicate, fine; feeble, fragile, frail; diaphanous, sheer, transparent Near Antonyms durable, knockabout, lasting, tough; coarse, heavy, rough, rude Antonyms sturdy, substantial

2 not likely to be true or to occur “The check is in the mail” is a pretty flimsy and tired excuse Synonyms doubtful, dubious, far-fetched, improbable, questionable, unapt, unlikelyRelated Words implausible, impossible, inconceivable, incredible, unbelievable, unimaginable, unthinkable; absurd, bizarre, crazy, fantastic (also fantastical), foolish, insane, nonsensical, odd, outlandish, preposterous, ridiculous, unreal, wild; outside, remote, slightNear Antonyms believable, conceivable, credible, earthly, imaginable, plausible; possible, potential; liableAntonyms likely, probable