\Wool"gath`er*ing\, a.
Indulging in a vagrant or idle exercise of the imagination;
roaming upon a fruitless quest; idly fanciful.

\Wool"gath`er*ing\, n.
Indulgence in idle imagination; a foolish or useless pursuit
or design.

      His wits were a woolgathering, as they say. --Burton.