past belief

astonishing implausible impossible improbable inconceivable incredible outlandish preposterous too much unimaginable unthinkable

beyond belief cockamamie cockeyed doubtful dubious far-fetched fishy flaky flimsy for the birds full of holes harebrained incogitable kooky lamebrained open to doubt phony questionable reaching scatterbrained screwy staggering suspect thick thin unconvincing unsubstantial weak won't hold water won't wash

believable conceivable credible imaginable likely plausible possible reasonable tenable

real