-en (1) Look up -en at Dictionary.com
word-forming element making verbs (such as darken, weaken) from adjectives or nouns, from Old English -nian, from Proto-Germanic *-inojan (also source of Old Norse -na), from PIE adjectival suffix *-no-. Most active in Middle English.
-en (2) Look up -en at Dictionary.com
suffix added to nouns to produce adjectives meaning "made of, of the nature of" (such as golden, oaken), corresponding to Latin -ine. Common in Old and Middle English, surviving words with it now are largely discarded in everyday use and the simple form of the noun serves as an adjective as well.