Source : Webster's Revised Unabridged Dictionary (1913)

Blue bonnet \Blue" bon`net\ or Blue-bonnet \Blue"-bon`net\, n.
   1. A broad, flat Scottish cap of blue woolen, or one wearing
      such cap; a Scotchman.

   2. (Bot.) A plant. Same as {Bluebottle}.

   3. (Zo["o]l.) The European blue titmouse ({Parus
      c[oe]ruleus}); the bluecap.