OED Definition:
The actions and sayings of Muhammad, viewed as complementing the divinely revealed message of the Qur’an, and constituting a source for establishing norms of conduct and, hence, a primary source of Islamic law; the paradigm or model of behaviour embodied in Muhammad’s example.
Term Variants: Sunna, Sunnah, Sunnat
The term Sunnah should always be explained when used, for example, as the practice of the Prophet Muhammad.
Sunnah is not to be confused with Sunni, the majority sect of Islam.
Sunnah (custom) refers to precedents of behaviour sourced from the life of the Prophet Muhammad (pbuh). The actions and sayings of Muhammad are reported in the Hadith, which were first systematised in the ninth and tenth centuries CE. [1] The example of the Prophet is believed “to complement the divinely revealed message of the Quran, constituting a source for establishing norms for Muslim conduct…”
These practices of the Prophet form a crucial pillar in the field of Islamic jurisprudence (Fiqh) where they complement the teachings in the Holy Quran.