Lynn Landlord-Tenant Lawyer, Massachusetts, page 2

A doctrine that prevents a defendant from re-litigating an issue after it has been lost. For example, if your neighbor sues you for putting up a fence on his land and the court rules that your fence extends beyond your property line, you can't later file your own lawsuit seeking a declaration that the property line is incorrectly drawn.

In a contract, a promise by one party not to hold the other party responsible if the other party carries out the contract in a way that causes damage to the first party. For example, many leases include a hold harmless clause in which the tenant agrees not to sue the landlord if the tenant is injured due to the landlord's failure to maintain the premises. In most states, these clauses are illegal in residential tenancies, but may be upheld in commercial settings.

A payment required by a landlord to ensure that a tenant pays rent on time and keeps the rental unit in good condition. If the tenant damages the property or leaves owing rent, the landlord can use the security deposit to cover what the tenant owes.

An exception to a zoning ordinance, usually granted by a local government. For example, if you own an oddly shaped lot that could not accommodate a home in accordance with your city's setback requirement, you could apply at the appropriate office for a variance allowing you to build closer to a boundary line.

(1) To formally grant power or authority to someone. For example, when the President of the United States is inaugurated, he is invested with all the powers of that office. (2) To contribute money to a business venture, or to buy property or securities, with the intention and expectation of making a profit.

A lawsuit brought by two parties, not as adversaries, but as collaborators in order to resolve a legal question that affects them both. For example, two companies might bring a friendly suit to court in order to clarify a legal interpretation of a contract between them.