Antonyms of adj confirmative

1 sense of confirmative

Sense 1
collateral, confirmative, confirming, confirmatory, corroborative, corroboratory, substantiating, substantiative, validating, validatory, verificatory, verifying -- (serving to support or corroborate; "collateral evidence")

INDIRECT (VIA supportive) -> unsupportive -- (not furnishing support or assistance)

Similarity of adj confirmative

1 sense of confirmative

Sense 1
collateral, confirmative, confirming, confirmatory, corroborative, corroboratory, substantiating, substantiative, validating, validatory, verificatory, verifying -- (serving to support or corroborate; "collateral evidence")
       => supportive (vs. unsupportive) -- (furnishing support or assistance; "a supportive family network"; "his family was supportive of his attempts to be a writer")