Antonyms of adj viable

2 senses of viable

Sense 1
feasible, executable, practicable, viable, workable -- (capable of being done with means at hand and circumstances as they are)

INDIRECT (VIA possible) -> impossible -- (not capable of occurring or being accomplished or dealt with; "an impossible dream"; "an impossible situation")

Sense 2
viable -- (capable of life or normal growth and development; "viable seeds"; "a viable fetus")

INDIRECT (VIA alive) -> dead -- (no longer having or seeming to have or expecting to have life; "the nerve is dead"; "a dead pallor"; "he was marked as a dead man by the assassin")

Similarity of adj viable

2 senses of viable

Sense 1
feasible, executable, practicable, viable, workable -- (capable of being done with means at hand and circumstances as they are)
       => possible (vs. impossible) -- (capable of happening or existing; "a breakthrough may be possible next year"; "anything is possible"; "warned of possible consequences")

Sense 2
viable -- (capable of life or normal growth and development; "viable seeds"; "a viable fetus")
       => alive (predicate) (vs. dead), live -- (possessing life; "the happiest person alive"; "the nerve is alive"; "doctors are working hard to keep him alive"; "burned alive"; "a live canary")