The Collaborative International Dictionary of English v.0.48:

Claymore mine \Clay"more mine`\ (kl[=a]"m[=o]r m[imac]n`), n.
   (Mil.)
   an antipersonnel land mine designed to produce a
   high-velocity spray of steel fragments in a relatively narrow
   fan-shaped cone, directed toward the enemy. They are usually
   detonated by an electrical remote control.
   [PJC]

WordNet (r) 3.0 (2006):

claymore mine
    n 1: an antipersonnel land mine whose blast is aimed at the
         oncoming enemy [syn: claymore mine, claymore]