expression, godan verb (-su)
give permission to marry
Used when a parent, guardian, or authority figure formally allows a couple to marry. Often implies a traditional or family context.
彼は彼女の両親に結婚を許してもらった。
He got permission to marry her from her parents.
結婚を認める is a more general term for acknowledging or approving a marriage, while 結婚を許す specifically implies granting permission, often from a parent or guardian.
A compound of 結婚 (marriage) + を (object marker) + 許す (to permit). The expression is transparent and follows standard Japanese grammar.