smithy n.

Middle English smith, from Old English smið "blacksmith, armorer, one who works in metal" (jewelers as well as blacksmiths), more broadly, "handicraftsman, practitioner of skilled manual arts" (also including carpenters), from Proto-Germanic *smithaz "skilled worker" (source also of Old Saxon smith, Old Norse smiðr, Danish smed, Old Frisian smith, Old High German smid, German Schmied, Gothic -smiþa, in aiza-smiþa "coppersmith"), from a suffixed form of PIE root *smi- "to cut, work with a sharp instrument" (source also of Greek smilē "knife for cutting and carving, chisel").

Attested as a surname by c. 975. Also used in a Middle English psalter of God, when he created light. Other common surnames meaning "smith" include Ferraro (Italian), Haddad (Arabic), Kovács (Hungarian, a Slavic loan-word), Kowalski (Polish), Herrero (Spanish), Kuznets (Russian), MacGowan (Irish, "son of the blacksmith").