1225-75;Middle English < Old Frenchtanesie, aphetic variant of atanesie < Medieval Latinathanasia < Greekathanasía immortality, equivalent to a-a-6 + thánat(os) death (see Thanatos) + -ia-y3, with ti < si
(Tanacetum vulgare), c.1265, from O.Fr. tanesie (13c.), from Gallo-Romance *tanaceta, from L.L. tanacetum "wormwood," from aphetic form of Gk. athanasia "immortality," so called probably for its persistence. English folklore associates it with pregnancy, either as an aid to contraception or to provoke miscarriage.