mésalliance

noun

més·​al·​liance ˌmā-ˌzal-ˈyäⁿs  ˌmā-zə-ˈlī-ən(t)s 

plural mésalliances ˌmā-ˌzal-ˈyäⁿs(-əz) 

ˌmā-zə-ˈlī-ən(t)-səz

: a marriage with a person of inferior social position

Word History

Etymology

French, from més- mis- + alliance

First Known Use

1782, in the meaning defined above