(economics) Any market in which trade is unregulated by government; an economic system free from government intervention.

(business) The buying and selling of goods through distribution channels other than those authorized or intended by the manufacturer or producer.

Any market in which carbon emissions trading takes place.

(marketing) The systematic collection and evaluation of data regarding customers' preferences for actual and potential products and services.

(finance) A market for trading short-term debt instruments, such as treasury bills, commercial paper, bankers' acceptances, and certificates of deposit.

drug on the market

(idiomatic) something which is overabundant at the moment and thus not in demand.

A market where meat is sold. / (colloquial, idiomatic) A place where one goes for a casual sexual encounter, such as a bar (establishment) or night club.

(Britain) The relatively small-scale growing of vegetables for market.

(obsolete) A market at which only samples of goods were available for sale.