Antonyms of adj mentally_ill

1 sense of mentally ill

Sense 1
mentally ill, unsound, unstable -- (suffering from severe mental illness; "of unsound mind")

INDIRECT (VIA insane) -> sane -- (mentally healthy; free from mental disorder; "appears to be completely sane")

Similarity of adj mentally_ill

1 sense of mentally ill

Sense 1
mentally ill, unsound, unstable -- (suffering from severe mental illness; "of unsound mind")
       => insane (vs. sane) -- (afflicted with or characteristic of mental derangement; "was declared insane"; "insane laughter")