complementary (acting as a complement; making up a whole with something else) · supplementary
köken: Learned borrowing from Koine Greek συμπληρωματικός (sumplērōmatikós) with semantic loan from French complémentaire and supplémentaire. By surface analysis, συμπληρωματ- (stem of συμπλήρωμα (symplíroma)) + -ικός (-ikós).