ὄνειος · oneios — LSJ
useful, most useful, serviceable, to the utmost, the most effectual remedy
useful, Nic. Al. 627, Hsch. (in form ὄνια) :—written ὄνιος in Tz.ad Lyc. 621, Suid. : Ion. Sup. ὀνήϊστος, η, ον (ος, ον prob. in Hp. Flat. 1, v. Hermes 46.274), most useful, serviceable, Anaxag. 4, Pythag. ap. D.L. 8.49 (cf. Call. Iamb. 1.132, 200), Heraclit. 121, Hp. l.c., Phoen. 4, Aret. CA 1.4, etc. ; ὀνήϊστον πονέεσθαι exert yourselves to the utmost, A.R. 2.335 ; ὕδρωπος ὀνήϊστα the most effectual remedy for the dropsy, Aret. CD 2.2.