Lewis Short
(adjective) : ŏpĭfer, ĕra, ĕrum, ops-fero
* Aidbringing, helping (poet. and in post-Aug. prose): deus,Ov. M. 15, 653: FORTVNA,Inscr. Orell. 1753.—Of things: folia,Plin. 16, 13, 24, § 64: fidem opiferam sociūm advocant, Enn. ap. Non. 144, 14 (p. 109, v. 165 Vahl.).
Charlton T. Lewis, Charles Short, A Latin Dictionary