noun
Anthropological term for marriage within a specific social group, clan, or tribe. Often contrasted with 族外婚 (exogamy).
See also: 族外婚
その部族では、長い間族内婚が続いてきた。
In that tribe, endogamy has been practiced for a long time.
族外婚 means exogamy, marriage outside one's own group, the opposite of 族内婚.
Compound of 族 (ぞく, 'tribe, clan') + 内 (ない, 'inside') + 婚 (こん, 'marriage').