Source : Webster's Revised Unabridged Dictionary (1913)

Rapier \Ra"pi*er\, n. [F. rapi[`e]re, perhaps for raspi[`e]re,
   and ultimately of German origin, akin to E. rasp, v.]
   A straight sword, with a narrow and finely pointed blade,
   used only for thrusting.

   {Rapier fish} (Zo["o]l.), the swordfish. [Obs.] --Grew.

Source : WordNet®

rapier
     n : a straight sword with a narrow blade and two edges [syn: {tuck}]