inproficient (adjective) incapable: not adequate; helpless
Sinonime: absurd, far-fetched, fishy,
flimsy*, implausible, impossible, improbable, incogitable,
inconceivable, insupposable, out of the question,
outlandish, phony,
preposterous,
questionable,
ridiculous, rings phony,
suspect, thin*, unbelievable, unconvincing, unimaginable, unsubstantial,
untenable, unthinkable
Antonime: believable,
credible,
plausible,
possible,
realistic, tenable