Antonyms of adj humpbacked

1 sense of humpbacked

Sense 1
crookback, crookbacked, humped, humpbacked, hunchbacked, gibbous, kyphotic -- (characteristic of or suffering from kyphosis, an abnormality of the vertebral column)

INDIRECT (VIA unfit) -> fit -- (physically and mentally sound or healthy; "felt relaxed and fit after their holiday"; "keeps fit with diet and exercise")

Similarity of adj humpbacked

1 sense of humpbacked

Sense 1
crookback, crookbacked, humped, humpbacked, hunchbacked, gibbous, kyphotic -- (characteristic of or suffering from kyphosis, an abnormality of the vertebral column)
       => unfit (vs. fit) -- (not in good physical or mental condition; out of condition; "fat and very unfit"; "certified as unfit for army service"; "drunk and unfit for service")