plant of the mint family, late 14c., from Old French thym, tym (13c.) and directly from Latin thymum, from Greek thymon, from PIE *dheu- (1), base of words meaning "to rise in a cloud" (see fume, n.); thus thyme might be the plant "having a strong odor," or it might be related to thyein "burn as a sacrifice," which would indicate the plant was used as incense. Related: Thymic.