The Collaborative International Dictionary of English v.0.48:

Carburize \Car"bu*rize\ (k[aum]r"b[-u]*r[imac]z), v. t. [imp. &
   p. p. Carburized; p. pr. & vb. n. Carburizing.] (Chem.)
   To combine with carbon or a carbon compound; -- said esp. of
   a process for conferring a higher degree of illuminating
   power on combustible gases by mingling them with a vapor of
   volatile hydrocarbons.
   [1913 Webster]

WordNet (r) 3.0 (2006):

carburize
    v 1: unite with carbon; "carburize metal" [syn: carbonize,
         carbonise, carburize, carburise]