Source : Webster's Revised Unabridged Dictionary (1913)

Trivet \Triv"et\, n. [Probably through French fr. L. tripes,
   -edis, three-footed; tri- (see {Tri-})+ pes, pedis, foot: cf.
   F. tr['e]pied. See {Foot}, and cf. {Tripod}.]
   1. A tree-legged stool, table, or other support; especially,
      a stand to hold a kettle or similar vessel near the fire;
      a tripod. [Written also {trevet}.]

   2. A weaver's knife. See {Trevat}. --Knight.

   {Trivet table}, a table supported by three legs. --Dryden.

Source : WordNet®

trivet
     n 1: a three-legged metal stand for supporting a cooking vessel
          in a hearth
     2: a stand with short feet used under a hot dish on a table