"one who grants a property as security for debt," 1580s, agent noun in Latin form from mortgage (v.). Native form mortgager is attested from 1630s. Barbarous mortgageor seems to be limited to legal writing.
Entries linking to mortgagor
mortgage v.
"to grant (immovable property) as security for money lent or contracted to be paid," late 15c., morgagen, from mortgage (n.). Related: Mortgaged; mortgaging.