Witless, a.
Destitute of wit or understanding; wanting thought; hence, indiscreet; not under the guidance of judgment. "Witless bravery." Shak. A witty mother! witless else her son. Shak. Witless pity breedeth fruitless love. Fairfax. -- Wit"less*ly, adv. -- Wit"less*ness, n.
Shades of meaning
Fernald lists witless only as an antonym, under clever.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given