Main water shut-off valve : The primary valve that halts the flow of water from the water meter into a home.

Mansard roof : A roof with four sides that slope upward from the roof edge to the square peak.

Manufactured housing : Prefabricated homes that can range from simple trailers to larger dwellings.

Mantel : The facing of stone, marble or other material around a fireplace.

Maintenance fee : The monthly assessment members of a homeowners' association pay for the repair and maintenance of common areas.

Managed-competition lots : Lots in which buyers choose between one of several builders.

Margin : The lender's "retail markup" on the mortgage. For example, if the index rate for an adjustable-rate mortgage is 5 percent but the lender has a 2.5 percentage-point margin, the rate the borrower will pay is 7.5 percent.

Market conditions : Factors affecting the sale and purchase of homes at a particular point in time.

Market value : The price that a piece of property sells for at a particular point in time.

Masonry : The brick or stone work on a building.

Master-planned community : A suburban plan that includes homes and commercial, work, educational and community facilities.

Maximum financing : A loan amount within 5 percent of the highest loan-to-value ratio allowed for a property.

Mechanical systems : A home's plumbing, wiring, heating and cooling systems.

Mechanic's lien : Subcontractors or suppliers sometimes will file an encumbrance, or mechanic's lien, against a property to seek payment.

Mediation : A dispute-resolution process in which a neutral party works to resolve contract differences.

Median price : The price of the house that falls in the middle of the total number of homes for sale in that area.

Merged credit report : A report that draws information from the Big Three credit-reporting companies: Equifax, Experian and TransUnion Corp.

Metes and bounds : A time-honored land surveying method of describing land in terms of shape and boundary dimensions.

Mint condition : Mint condition, or blue-ribbon condition, refers to a house that looks as close to new as possible.

Mixed-income housing : A neighborhood that contains houses of widely varying prices.

Mixed-use development : A project that combines several different functions, such as residential space above a commercial establishment or an entire development combining commercial, residential and public accommodations.

Modification : A change in any of the terms of the loan agreement.

Molding : Decorative trim elements applied to walls, ceilings, and window and door openings.

Money market account : Accounts that work like money market funds and allow individual investors to participate in certain managed investments and withdraw funds under most conditions.

Money market funds : A mutual fund that pools the resources of individuals to invest in certain managed investments.

Mortgage : A legal document specifying a certain amount of money to purchase a home at a certain interest rate, and using the property as collateral.

Mortgagee : A bank or other financial institution that lends money to the borrower. The borrower is considered the mortgagor.

Mortgagor : The person who borrows money to purchase a house. The lender is called the mortgagee.

Mortgage acceleration clause : A clause which allows a lender to demand that the entire balance of the loan be repaid in a lump sum under certain circumstances. The acceleration clause is usually triggered if the home is sold, title to the property is changed, the loan is refinanced or

Mortgage banker : A company that provides home loans using its own money. The loans are usually sold to investors such as insurance companies and Fannie Mae.

Mortgage broker : A company that matches lenders with prospective borrowers who meet the lender's criteria. The mortgage broker does not make the loan, but receives payment from the lender for services.

Mortgage insurance : Required by lenders in some loans to protect them from a possible default . All conventional loans with less than a 20 percent down payments require private mortgage insurance, or PMI.

Mortgage-interest deduction : The tax write-off that the Internal Revenue Service allows most owners to claim for the annual interest payments they make on their real estate loans.

Mortgage life insurance : A special type of insurance that will pay off a mortgage if the borrower dies before the debt is retired.

Motivated buyer : Any buyer with a strong incentive to make a purchase.

Motivated seller : Any seller with a strong incentive to make a deal.

Move-in condition : A house that is ready for a new occupant.

Move-up buyer : A buyer who has purchased a home before and is looking for a bigger or more expensive home.

Mullion : A vertical dividing bar between window lights or panels.

Multidwelling property : A property that contains individual units for several households but carries only one mortgage.

Multifamily mortgage : A mortgage on a multifamily dwelling with more than four families, typically an apartment building.

Multiple listing service (MLS) : The service combines the listings for all available homes in an area, except For-Sale-By-Owner (FSBO) properties, in one directory or database.

Multiple offers : Multiple purchase offers occur in hot markets or hot neighborhoods.

Municipal housing inspector : Inspectors employed by cities or counties to check all construction sites and verify that contractors are meeting building codes.