Covin an association of persons, so used in the Statute of Labourers of 1360, which, inter alia, declared void all alliances and covins of stonemasons and carpenter

Carpenter

A carpenter is a skilled craftsperson who works with timber to construct, install and maintain buildings, furniture, and other objects. The work, known as carpentry, may involve manual labor and work outdoors....

s.

The more common use of the term in English law

English law

English law is the legal system of England and Wales, and is the basis of common law legal systems used in most Commonwealth countries and the United States except Louisiana...

 was for a secret agreement between persons to cheat and defraud, but the word is now obsolete, and has been superseded by collusion or conspiracy

Conspiracy (crime)

In the criminal law, a conspiracy is an agreement between two or more persons to break the law at some time in the future, and, in some cases, with at least one overt act in furtherance of that agreement...

to cheat and defraud.
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