adjective
not plausible or readily believable
an implausible explanation
Synonyms: flimsy, improbable, inconceivable, incredible, thick, thin, unbelievable, unconceivable, unconvincing, unsubstantial, weak; compare tenuous 3
Related Word: doubtful, dubious, fishy; problematic, puzzling, suspect
Idioms: a bit thick
Contrasted words: meaty, pithy; solid, sound, substantial; believable, conceivable, credible; likely, probable
Antonyms: plausible