When the word enamel was first used in the English language in fifteenth-century health books, it was in its verb form, describing the action of encrusting something with what we now call enamel. It developed into a noun about a hundred years later, peaked in usage in the 1940s, and has been decreasing in popularity since. Through Middle English, enamel comes from Anglo-Norman enamailler, which is sort of redundant because it contains the prefix en-, meaning "in", and the root amailler, meaning "to enamel", which is exactly what we started with. Going back further, we can trace the term through Old French esmailler and esmal, both with the same definition. Possibly by way of Frankish smalt, that further would derive from the Proto-Germanic reconstruction smaltjana, meaning "to smelt". Today, that early word is survived by enamel's cognates in German schmelzen and Danish smelte, both "melt".
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.