1801, "stimulate by galvanic electricity," from French galvaniser, from galvanisme (see galvanism). Figurative sense of "excite, stimulate (as if by electricity)" first recorded 1853 (galvanic was in figurative use in 1807). Meaning "to coat with metal by means of galvanic electricity" (especially to plate iron with tin, but now typically to plate it with zinc) is from 1839.
He'll swear that in her dancing she cuts all others out,
Though like a Gal that's galvanized, she throws her legs about.
[Thomas Hood, "Love has not Eyes," 1845]
Related: Galvanized; galvanizing.