Source : Webster's Revised Unabridged Dictionary (1913)

Cobweb \Cob"web`\, n. [Cob a spider + web.]
   1. The network spread by a spider to catch its prey.

   2. A snare of insidious meshes designed to catch the ignorant
      and unwary.

            I can not but lament thy splendid wit Entangled in
            the cobwebs of the schools.           --Cowper.

   3. That which is thin and unsubstantial, or flimsy and
      worthless; rubbish.

            The dust and cobwebs of that uncivil age. --Sir P.
                                                  Sidney.

   4. (Zo["o]l.) The European spotted flycatcher.

   {Cobweb lawn}, a fine linen, mentioned in 1640 as being in
      pieces of fifteen yards. --Beck. Draper's Dict.

            Such a proud piece of cobweb lawn.    --Beau. & Fl.

   {Cobweb micrometer}, a micrometer in which threads of cobweb
      are substituted for wires.

Source : WordNet®

cobweb
     n 1: filaments from a cobweb [syn: {gossamer}]
     2: a dense elaborate spider web that is more efficient than the
        orb web