The Collaborative International Dictionary of English v.0.48:

Witless \Wit"less\, a.
   Destitute of wit or understanding; wanting thought; hence,
   indiscreet; not under the guidance of judgment. "Witless
   bravery." --Shak.
   [1913 Webster]

         A witty mother! witless else her son.    --Shak.
   [1913 Webster]

         Witless pity breedeth fruitless love.    --Fairfax.
   [1913 Webster] -- Wit"less*ly, adv. -- Wit"less*ness, n.
   [1913 Webster]