The Collaborative International Dictionary of English v.0.48:

Cuttystool \Cut"ty*stool`\ (-st[=oo]l`), n.
   1. A low stool. [Scot.]
      [1913 Webster]

   2. A seat in old Scottish churches, where offenders were made
      to sit, for public rebuke by the minister.
      [1913 Webster]