Source : Webster's Revised Unabridged Dictionary (1913)

Cockshut \Cock"shut`\, n.
   A kind of net to catch woodcock. [Obs.] --Nares.

   {Cockshut time} or {light}, evening twilight; nightfall; --
      so called in allusion to the tome at which the cockshut
      used to be spread. [Obs.] --Shak. B. Jonson.