early 14c., from Anglo-French enamailler (early 14c.), from en- "in" (see en-(1)) + amailler "to enamel," variant of Old French esmailler, from esmal "enamel," from Frankish *smalt, from Proto-Germanic *smaltjan "to smelt" (see smelt, v.). Related: Enameled; enameler; enameling.

early 15c., in ceramics, from enamel, v.. As "hardest part of a tooth," 1718, from a use in French émail.