Source : Webster's Revised Unabridged Dictionary (1913)

Grommet \Grom"met\, n. [F. gourmette curb, curb chain, fr.
   gourmer to curb, thump, beat; cf. Armor. gromm a curb, gromma
   to curb.]
   1. A ring formed by twisting on itself a single strand of an
      unlaid rope; also, a metallic eyelet in or for a sail or a
      mailbag. Sometimes written {grummet}.

   2. (Mil.) A ring of rope used as a wad to hold a cannon ball
      in place.

Source : WordNet®

grommet
     n : fastener consisting of a metal ring for lining a small hole
         to permit the attachment of cords or lines [syn: {cringle},
          {eyelet}, {loop}, {grummet}]