Antonyms of adj vanquishable

1 sense of vanquishable

Sense 1
beatable, vanquishable, vincible -- (susceptible to being defeated)

INDIRECT (VIA conquerable) -> unconquerable -- (not capable of being conquered or vanquished or overcome; "a tribute to his courage...and his unconquerable will"- R.E.Danielson; "faced unconquerable difficulties")

Similarity of adj vanquishable

1 sense of vanquishable

Sense 1
beatable, vanquishable, vincible -- (susceptible to being defeated)
       => conquerable (vs. unconquerable) -- (subject to being conquered or overcome; "knew her fears were ultimately conquerable")