Usage: 2 forms in 2 verses
Form Translated As     In Verse(s)
εγαμβρεύσατο Solomon contracted a marriage LXX.1Kgs.3.1
γαμβρεύσητε contract a marriage LXX.Deut.7.3

Liddell-Scott-Jones

γαμβρεύω (gambreuō) to marry G:V

γαμβρεύω,

form connexions by marriage, πρός τινας [LXX]:—middle, marry, variant [LXX]:—passive, to be connected by marriage, τινί [Refs 1st c.AD+]

LSJ Scripture Refs: LXX.Deut.7.3LXX.Gen.38.8