a. | 1. | Not credible; surpassing belief; too extraordinary and improbable to admit of belief; unlikely; marvelous; fabulous. |
Adj. | 1. | incredible - beyond belief or understanding; "at incredible speed"; "the book's plot is simply incredible" Synonyms: unbelievable Antonyms: believable, credible - capable of being believed; "completely credible testimony"; "credible information" |