Synonyms for Witless:

adj.

daft (adjective)
demented, deranged, foolish, idiotic.
dull (adjective)
insensate, simple-minded.
foolish (adjective)
fatuous.
mindless (adjective)
nitwitted.
witless (adjective)
brainless, idiotic, senseless, silly, unintelligent.

n.

ability, brainless, fatuous, foolish, idiotic, insensate, planned, silly, simple-minded, unintelligent, Weak-minded. mentally ill (noun)
bipolar, certifiable, confused, demented, depressed, deranged, hysterical, diminished responsibility.
witless (noun)
nitwitted, senseless, soft-witted.

Other synonyms:

brainless. fatuous, foolish, silly, unintelligent, Weak-minded. insensate. Other relevant words:
brainless, confused, demented, deranged, fatuous, foolish, idiotic, insensate, senseless, silly, simple-minded, unintelligent, Weak-minded.

Usage examples for witless

  1. Words thou never shouldst exchange with a witless fool; 125. For from an ill- conditioned man thou wilt never get a return for good; but a good man will bring thee favour by his praise. – The Elder Eddas of Saemund Sigfusson; and the Younger Eddas of Snorre Sturleson by Saemund Sigfusson and Snorre Sturleson
  2. " But do let her go, Jacky," coaxed his poor witless wife. – Tess of the d'Urbervilles A Pure Woman by Thomas Hardy
  3. " Say rather," said Hircan, " what a foolish and witless mother to be led by hypocrisy into allowing so much familiarity to those who ought never to be seen except in church." – The Tales Of The Heptameron, Vol. IV. (of V.) by Margaret, Queen Of Navarre