Extended Strong's Greek Lexicon (Abbott-Smith based)
opportune
Usage: εὔ-καιρος, -ον [in LXX: Psa.104:27 (עֵת), 2Ma.14:29 2Mac 15:20-21, 3Ma.4:11 3Mac 5:44 * ;] timely, seasonable, suitable (Cremer, 740): ἡμέρα, Mrk.6:21 (or empty, as in Byz. and MGr.; see MM, Exp., xiv); βοήθεια, Heb.4:16.† (AS)