A circle in which filled with lame/uninteresting people, bitches or people that you dislike, or some sort of disagreement; philosophy, idealistic ways, knowledge etc. And or a circle devoid of and interesting subject, Or a combination of the two

When you beat off to geometry

Someone who accelerates when entering a traffic circle to cut off other drivers travelling at normal speeds.

Someone who is being a genuine douchebag on Google+. They can either be making a bunch of really stupid updates, making rude comments on your posts, or +1ing updates about your grandmother dying.

A circle jerk is the abrupt, jerking stop after pulling the handbrake while doing doughnuts in a car.

When Males sit in a circle and jack off and they all ejaculate on a piece of bread in the middle and last one to ejaculate has to eat the bread.

The practice of expressing emotions, feelings, and impractical sentiments as a means of bonding or gaining appreciation for the members of your team. Related activities may include, but are not limited to making lists, repeatedly affirming one's consent with another persons already expressed opinion, etc.

Oftentimes 'circle-jerking' will occur during meeting times when people feel the need to express their own opinions over and over for the sake of hearing their own voice. Furthermore, they will speak in circles, never actually reaching a point, therefore, appearing like a total jerk off...the entire session then seems like youve experienced a circle-jerk.