adj. (old).Inconsiderate; thoughtless; easily imposed on; Wild-headed, not Solid or Stayed, opposed to a Sober Wit (B. E. and GROSE).
1605. BACON, The Advancement of Learning, II. (1861), 228. If a child be BIRD-WITTED, that is, hath not the faculty of attention, the mathematics giveth a remedy thereunto.
1650. USSHER, Annals, VI., 360. [He] proved but a BIRD-WITTED man.