joint enterprise n1 : joint venture
2 : an undertaking of two or more parties for a common purpose in which each shares a common interest and an equal right of control (as of a vehicle) NOTE: In regard to a tort involving such an enterprise, a third party may impute negligence of one party (as a driver) to another in the enterprise.
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.