The Collaborative International Dictionary of English v.0.48:

Doit \Doit\ (doit), n. [D. duit, Icel. pveit, prop., a piece cut
   off. See Thwaite a piece of ground, Thwite.]
   1. A small Dutch coin, worth about half a farthing; also, a
      similar small coin once used in Scotland; hence, any small
      piece of money. --Shak.
      [1913 Webster]

   2. A thing of small value; as, I care not a doit.
      [1913 Webster]