Wiktionary
n. 1 A marriage in which the partners decide not to have children, and to reserve the right to divorce amicably with mutual consent 2 (context social history anthropology English) A conception of marriage where complicity, communication and support between spouses are considered important, rather than purely material questions of inheritance etc.
Wikipedia
Companionate Marriage was a 1928 American silent drama film directed by Erle C. Kenton and starring Betty Bronson, and released by First National Pictures. The film is now considered lost.
The film was a collaboration between the company of Asher Small Rogers and Sam Sax. It was banned by the New York State Censor.
Usage examples of "companionate marriage".
Dalla was as decorative as she was competent, and this had led to a few episodes that made her first companionate marriage to Verkan Vall rather hectic.