Lewis & Short

ăgērăton, i, n., = ἀγήρατον (not growing old), a plant that does not readily wither, perhaps Achillea Ageraton, Linn.; Plin. 27, 4, 4, § 13.Ăgērătos, i, m., a designation of one of the Æons of Valentinus, Tert. adv. Val. 8.