Definition from Wiktionary, the free dictionary
co-husband (plural co-husbands)
- In a polyandrous marriage, another husband of a man's wife.
1997, David Lipset, Mangrove man: dialogics of culture in the Sepik estuary, page 72:
- When younger brother calls [his elder brother's wife] his "co-wife" and reciprocally, when she calls him "co-husband," rights in sexuality are being satirized.
2004, Govindraraj Sulekha, The Co-husband:
- The village chief Sambhu, upheld Mahesh’s claim to half of Damodar’s wealth since he was his co-husband