noun
peer group
A social group consisting of individuals of similar age, status, or interests, often used in sociological or educational contexts.
思春期には仲間集団の影響が大きくなる。
During adolescence, the influence of peer groups becomes stronger.
Compound of 仲間 (nakama, 'companion, colleague') and 集団 (shūdan, 'group, collective'). The exact historical derivation is uncertain, but the term is a straightforward modern combination.