المعنى الاصطلاحي

A man's children and his father's children, males and females, down the family tree line.

الشرح المختصر

Shia sects have divergent views concerning the meaning of the term ‘itrah (household). Some of them limited the term to ‘Ali, Al-Hasan, Al-Husayn and nine imams from the offspring of Al-Husayn. Those are the Rāfidah Ithna ‘Ashriyyah (the Twelvers). Others limited the term to the offspring of Ismā‘īl ibn Ja‘far, and those are the Ismā‘īliyyah. All the Shia sects, however, claim that all those persons are infallible. Ahl-us-sunnah wa al-Jamā‘ah's approach is to adhere to the Book of Allah and the sunnah of His Prophet, may Allah's peace and blessings be upon him. They observe the right of the ‘itrah, i.e. the household of the Prophet, may Allah's peace and blessings be upon him, maintain their honor, but do not restrict the truth to them, nor they believe that compliance is to be exclusively due to them.

التعريف اللغوي المختصر

"‘Itrah": a man's children and offspring, also his clan and relatives, the close and the distant thereof. It is derived from "‘atr", which means branching out or intensifying. "‘Itr": origin, ancestry. Relatives are called "‘itrah" because their lineages are branched out or because one cares for them intensely.