As used in this act:
(a) "Mortgage loan" means a loan secured by an interest in real property consisting of land upon which is erected or to be erected, in whole or in part with the proceeds of such loan, a structure containing one, two, three, four, five or six dwelling units, a portion of which structure may be used for nonresidential purposes and upon which interest is taken or contracted for at a rate in excess of $6.00 for the forbearance of $100.00 for a year;
(b) "Mortgagor" includes any person other than a corporation liable for the payment of a mortgage loan, and the owner of the real property which secures the payment of a mortgage loan;
(c) "Prepayment" of a mortgage loan means the payment in full of the balance owing on a mortgage loan at any time prior to the time limited for the final payment of such loan in an instrument evidencing such loan.