Second mortgage
A mortgage made subsequent to another mortgage and subordinate to the first one.

Security
A financial instrument showing ownership of equity (such as common stock), indebtedness (such as a debt security), a group of mortgages (such as MBS), or potential ownership (such as an option).

Seller carry-back
An agreement in which the owner of a property provides financing, often in combination with an assumable mortgage.

Serious delinquency
A single-family mortgage that is 90 days or more past due, or a multifamily mortgage that is two months or more past due.

Servicer
An organization that collects principal and interest payments from borrowers and manages borrowers' escrow accounts. The servicer often services mortgages that have been purchased by an investor in the secondary mortgage market.

Servicing
All steps and operations a lender performs to keep a loan in good standing, such as collection of payments, payment of taxes, insurance, and property inspections.

Simple interest
Interest which is computed only on the principle balance.

Special assessments
A special tax imposed on property, individual lots or all property in the immediate area, for road construction, sidewalks, sewers, street lights, etc.