c. 1400, "process of tanning," from Old French tannerie (13c.) or a native formation from tan (v.) + -ery. Meaning "place where tanning is done" is from 1736, perhaps from tanner (n.1) + -y (2).
tank top
tanka
tankard
tanker
tanner
tannery
tannin
tanning
tansy
tantalise
tantalize