espouse (v.) Look up espouse at Dictionary.com
mid-15c., "to take as spouse, marry," from Old French espouser "marry, take in marriage, join in marriage" (11c., Modern French épouser), from Latin sponsare, past participle of spondere (see espousal).

Extended sense of "adopt, embrace" a cause, party, etc., is from 1620s. Related: Espoused; espouses; espousing. For initial e-, see especial.