Source : Webster's Revised Unabridged Dictionary (1913)

Tappit hen \Tap"pit hen`\
   1. A hen having a tuft of feathers on her head. [Scot.]
      --Jamieson.

   2. A measuring pot holding one quart (according to some,
      three quarts); -- so called from a knob on the lid,
      thought to resemble a crested hen. [Scot.] --Jamieson.