(idiomatic,informal,now usually with "of") To marry (a woman), especially if there is an existing sexual relationship.
I thought about just asking Rosalyn to move in with me, but I decided it was time to make an honest woman out of her.
1749, Henry Fielding, Tom Jones, Folio Society 1973, p. 567:
the mother, Mr Jones, Mr Nightingale, and his love, stept into a hackney-coach, which conveyed them to Doctors' Commons; where Miss Nancy was, in vulgar language, soon made an honest woman, and the poor mother became […] one of the happiest of all human beings.
Usage notes
Also with "out of" for "of", especially in US English.