cliques

Example:He was part of a gang of lads who always found ways to cause trouble.

Definition:a group of people who are united by strong bonds of friendship or shared interests and who may engage in illegal or antisocial behavior.

Example:Everyone knew that the circle of friends was tight and didn't allow anything or anyone to disturb the harmony.

Definition:a group of people who share a common interest or background and often exclude others.

Example:She felt isolated in the set of people around her boss, everyone seemed to support her except for the clique.

Definition:a group of people who share a common interest, occupation or vocation and often form a social unit.