Source : Webster's Revised Unabridged Dictionary (1913)

Thrum \Thrum\, n. [OE. thrum, throm; akin to OD. drom, D. dreum,
   G. trumm, lump, end, fragment, OHG. drum end, Icel. ?r["o]mr
   edge, brim, and L. terminus a limit, term. Cf. {Term}.]
   [Written also {thrumb}.]
   1. One of the ends of weaver's threads; hence, any soft,
      short threads or tufts resembling these.

   2. Any coarse yarn; an unraveled strand of rope.

   3. (Bot.) A threadlike part of a flower; a stamen.

   4. (Mining) A shove out of place; a small displacement or
      fault along a seam.

   5. (Naut.) A mat made of canvas and tufts of yarn.

   {Thrum cap}, a knitted cap. --Halliwell.

   {Thrum hat}, a hat made of coarse woolen cloth. --Minsheu.