adj.不合理的，难以置信的
Merriam-Webster Online Dictionary
implausible (adjective) not plausible provoking disbelief
Merriam-Webster Online Thesaurus
implausible (adjective)too extraordinary or improbable to believe
SYNONYMS:
fantastic ( fantastical), implausible, inconceivable, incredulous, unbelievable, uncompelling, unconceivable, unconvincing, unimaginable, unthinkableRELATED WORDS:
debatable, disputable, dodgy [], doubtable, doubtful, dubious, dubitable, far-fetched, fishy, flimsy, questionable, shaky, suspect, suspicious, unlikely, unreasonable; hopeless, impossible; absurd, comical, farcical, laughable, ludicrous, outlandish, preposterous, ridiculous, risible, silly; indefensible, insupportable, untenableNEAR ANTONYMS:
likely, possible, probable; reasonable; certain, incontestable, indisputable, indubitable, questionless, sure, undeniable, undoubted, unquestionable