Quantum
Latin: amount or extent.

Quantum meruit
Latin for "as much as is deserved." This is a legal principle under which a person should not be obliged to pay, nor should another be allowed to receive, more than the value of the goods or services exchanged.

Quasi-judicial
Refers to decisions made by administrative tribunals or government officials to which the rules of natural justice apply. In judicial decisions, the principles of natural justice always apply. But between routine government policy decisions and the traditional court forums lies a hybrid, sometimes called a "tribunal" or "administrative tribunal" and not necessarily presided by judges. These operate as a government policy-making body at times but also exercise a licensing, certifying, approval or other adjudication authority which is "judicial" because it directly affects the legal rights of a person. Some law teachers sugest that there is no such thing as a "quasi-judicial" decision or body; the body or decision is either judicial or not.

Quid pro quo
Latin: something for something. The giving of something in exchange for another thing of equal value.

Quo warranto
Latin and referring to a special legal procedure taken to stop a person or organization from doing something for which it may not have the legal authority, by demanding to know by what right they exercise the controversial authority.

Quorum
The number of people who must be present at a meeting before business can be conducted. Without "quorum", decisions are invalid. Many organizations have a quorum requirement to prevent decisions being taken without a majority of members present.

QW
Quarterly Wage