Where does “open marriage” come from?

open marriage (English) comes from English marriage, from Middle English mariage, from Old French mariage, from Old French marier, from Latin marītō, from Latin marītus, from Latin mās, from Proto-Nuristani *māsa — to measure.

open marriage (English): A marital relationship in which both partners mutually agree that each is free to have sexual relationships with other people as they choose

Definitions

  1. A marital relationship in which both partners mutually agree that each is free to have sexual relationships with other people as they choose

Ancestry of “open marriage”, step by step

open marriage traces back through two separate lines of ancestry.

via English marriage

StepLanguageWordMeaning
1EnglishmarriageThe state of being married; A union of two or...
2Middle Englishmariagemarriage
3Old Frenchmariagemarriage; wedding
4Old Frenchmarierto marry; to get married
5Latinmarītōto marry, wed
6Latinmarītusmarital, matrimonial, conjugal
7Latinmāsmale
8Proto-Nuristani*māsamoon
9Proto-Indo-Iranianmā́Hasmoon; month
10Proto-Indo-Europeanmḗh₁n̥smoon; month
11Proto-Indo-Europeanmeh₁-to measure

via English open

StepLanguageWordMeaning
1EnglishopenNot closed; Not physically drawn together,...
2Middle Englishopenopen
3Old Englishopenopen
4Proto-West Germanic*opanopen
5Proto-Germanicupanazopen
6Proto-Indo-Europeanupóunder, below
7Proto-Indo-Europeanh₃ewp-
Every word from Proto-Indo-European meh₁-Every word from Proto-Indo-European mḗh₁n̥sEvery word from Proto-Indo-Iranian mā́Has