Antonyms of adj impugnable

1 sense of impugnable

Sense 1
impugnable -- (subject to being discredited)

INDIRECT (VIA questionable) -> unquestionable -- (incapable of being questioned; "unquestionable authority")

Similarity of adj impugnable

1 sense of impugnable

Sense 1
impugnable -- (subject to being discredited)
       => questionable (vs. unquestionable) -- (subject to question; "questionable motives"; "a questionable reputation"; "a fire of questionable origin")