mentally ill

1. 1.

   suffering from severe mental illness

   “of unsound mind”

   Synonymsunsoundunstable

   Similarinsane

Questions about mentally ill

What does mentally ill mean?

mentally ill means "suffering from severe mental illness".

What is another word for mentally ill?

Close synonyms include unsound, unstable. Each sense on this page lists its own synonyms, because a word with several meanings rarely has one substitute that works for all of them.

Is mentally ill a common word?

mentally ill is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.