1) the linguistic process that explains a word of a closed class as produced out of one in an open class; 2) the deeper process of allowing a pattern of linguistic signs to represent conventional concepts, ¶3-2-3.

The process by which a content word comes to have only functional meaning; for example, the Old English nouns h~d "state, quality" and l§c "body" have become the Modern English suffixes "-hood" and "-ly" (McMahon, p.160).