adj.

untanable; unbelievable (malagnana); incredible; improbable (hard to believe • "Young man," he said, "upon this point I can only say that your story is grossly improbable. It won't hold water."; an improbable explanation); anecdotic; fabulous; steep; unlikely (not likely or probable); unthinkable; uncreditable; unplausible; impossible; farfetched (xenkis); larger-than-life (Anglophile); ludicrous (Tanya Gesse); increditable (Допустимо как increditable так и uncreditable Sin21); far-fetched (extremely unlikely to be true or to happen Senior Strateg); unlike; wide of truth; specious; off the mark (I don't think this story of his is far off the mark. – По мне так эта его история не такая уж и неправдоподобная. maqig)

out-of-this-world (figure of speech Val_Ships)

flimsy (Vadim Rouminsky)

fat-fetched (great_manul)

steep (о рассказе); steeper (о рассказе); fishy

ridiculous (Vadim Rouminsky)

reach (peacemaker)

неправдоподобный

: 73 phrases in 20 subjects