First mortgage
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
The first (in time or right) of a series of two or more mortgages covering the same property and successively attaching as liens upon it; also, in a more particular sense. a mortgage which is a first lien on the property, not only as against other mortgages, but as against any other charges or incumbrances.
Green's Appeal, 07 Pa. 347.