{i} mutual assistance, practice of working together in order to attain a particular goal (in politics, etc.); rolling of logs from one place to another
act of exchanging favors for mutual gain; especially trading of influence or votes among legislators to gain passage of certain projects
Hence: A combining to assist another in consideration of receiving assistance in return; sometimes used of a disreputable mode of accomplishing political schemes or ends
The act or process of rolling logs from the place where they were felled to the stream which floats them to the sawmill or to market
Mutual recommendation of friends or colleagues services or products. Commonly used in the context of book recommendations in literary reviews etc