Adat

Despite its Arabic origin, the term adat resonates deeply throughout Maritime Southeast Asia, where due to colonial influence, its usage has been systematically institutionalised into various non-Muslim communities.

The word adat is derived from the Arabic ʿādā́t (عادات), the plural form of ʿā́da (عادَة), meaning custom, or habit, and is considered synonymous with urf (عرف), something which is commonly known or accepted.

[5] In the North Caucasus, the traditional value codex of adat held that the Teip ('clan') was the chief reference for loyalty, honor, shame, and collective responsibility.

[7] In Southeast Asia, the concept of adat and its meanings were first formulated in the Islamised Malay-speaking world, apparently to distinguish non-Islamic from Islamic practices.

Local indigenous laws and customs of all ethnic groups, including those of non-Muslims, began to be collectively termed as "adat" and were encoded into units of jural management, whereby legal pluralism in the East Indies was introduced.

[14][15] Legal proceedings on matters related to Islamic affairs and adat (such as harta sepencarian or 'matrimonial property' cases) are carried out in Syariah Court.

[17] In the North Caucasus, traditional, clan-based systems of self-government, which had been functioning underground since the 1950s, began to reappear in response to the federal government's neglect and local administrative impotence.

Adat perpatih, confined almost exclusively to Negeri Sembilan, where dwell the descendants of the Minangkabau immigrants from West Sumatra, is associated with a matrilineal rule of descent and a political structure based upon the kinship system.