The Collaborative International Dictionary of English v.0.48:

Burin \Bu"rin\, n. [F. burin, cf. It. burino, bulino; prob. from
   OHG. bora borer, bor[=o]n to bore, G. bohren. See 1st
   Bore.]
   1. The cutting tool of an engraver on metal, used in line
      engraving. It is made of tempered steel, one end being
      ground off obliquely so as to produce a sharp point, and
      the other end inserted in a handle; a graver; also, the
      similarly shaped tool used by workers in marble.
      [1913 Webster]

   2. The manner or style of execution of an engraver; as, a
      soft burin; a brilliant burin.
      [1913 Webster]

WordNet (r) 3.0 (2006):

burin
    n 1: a chisel of tempered steel with a sharp point; used for
         engraving