Source : Webster's Revised Unabridged Dictionary (1913)

Quirk \Quirk\, n. [Written also {querk}.] [Cf W. chwiori to turn
   briskly, or E. queer.]
   1. A sudden turn; a starting from the point or line; hence,
      an artful evasion or subterfuge; a shift; a quibble; as,
      the quirks of a pettifogger. ``Some quirk or . . .
      evasion.'' --Spenser.

            We ground the justification of our nonconformity on
            dark subtilties and intricate quirks. --Barrow.

   2. A fit or turn; a short paroxysm; a caprice. [Obs.]
      ``Quirks of joy and grief.'' --Shak.

   3. A smart retort; a quibble; a shallow conceit.

            Some odd quirks and remnants of wit.  --Shak.

   4. An irregular air; as, light quirks of music. --Pope.

   5. (Building) A piece of ground taken out of any regular
      ground plot or floor, so as to make a court, yard, etc.;
      -- sometimes written quink. --Gwilt.

   6. (Arch.) A small channel, deeply recessed in proportion to
      its width, used to insulate and give relief to a convex
      rounded molding.

   {Quirk molding}, a bead between two quirks.