Carburize comes from carbon (via carburet) + -ize. Carbon is from French carbone, from Latin carbō ('coal, charcoal'). The historical trail runs through carbō in Latin. Morphologically, carburize is transparent: it draws on carbon (via carburet) + -ize. Used as a verb, carburize now means "harden the surface of iron or steel by adding carbon", so the present definition can be read against the older forms and meanings. The same lexical family is also visible in derived forms such as carburization and related forms such as carbon and carburet. The result is a borrowed or transmitted form whose modern spelling carries a compact record of its route into English.