When you gang up on a goody-goody and form a circle and push him/her around. Usually you yell "NERD CIRCLE!" while pushing them around.

Large, beautiful breasts that are keep well consealed and initially appear to be much smaller and less impressive than they actually are until unleashed.

When a group of 3 or more non-nerds surround a nerd and push him/her back and forth around said circle.

A nerd circle is when a group of nerds get together and form a circle with laptop or desktop computers and play a (massie multiplayer online game) mmo for example world of warcraft or everquest 2