Adjective: unbelievable ,ún-bi'lee-vu-bul
- Beyond belief or understanding
"at unbelievable speed";
- incredible
- Having a probability too low to inspire belief
"His unbelievable excuse didn't fool anyone";
- improbable, unconvincing, unlikely, doubtful
See also: astounding, believability, credibility, credibleness, dumbfounding, dumfounding, fabulous, flimsy, implausible, improbable, incredulous, marvellous [Brit, Cdn], marvelous [US], tall, unconvincing, undreamed, undreamed of, undreamt, undreamt of, unimagined, unthinkable
Encyclopedia: Unbelievable