Extended Strong's Greek Lexicon (Abbott-Smith based)
mutual consent
Usage: σύμφωνος, -ον (ούν, φωνή), [in LXX: Ecc.7:14 (עֻמָּה), 4Ma.7:7 4Mac 14:7 * ;] agreeing in sound. Metaphorical, harmonious, agreeing: ἐκ συμφώνου (for exx. from π., see Deiss., BS, 255), by agreement, 1Co.7:5.† (AS)