Synonyms of unfeasible

2 Syllables
no-go, no-way, noway
3 Syllables
utopian, nonviable
4 Syllables
impossible, unreachable, ungettable, pie-in-the-sky, impractical, unworkable, infeasible
5 Syllables
inapproachable, unsustainable, unnegotiable, unattainable, inaccessible, impracticable, irrealizable, unachievable, unserviceable, unobtainable, unrealizable
6 Syllables
unbusinesslike