1. vulgar slang A gathering in which males masturbate ("jerk off") together, perhaps while standing in a circle.
2. vulgar slang By extension, something that is ultimately pointless but pleases and gratifies the participants. The so-called "group discussion" was just a circle jerk of people who love to hear themselves talk.
1. n. a gathering of males performing mutual masturbation. (Partly jocular. Usually objectionable.) There were twelve boys involved in a circle-jerk, and the principal caught them.
2. n. a boring or time-wasting meeting. (From sense 1) That board meeting was the typical circle-jerk that it always is.