1970s. From Arabic muṭṭawwiʿ (in colloquial pronunciation muṭṭawwaʿ) (plural muṭṭawwiʿa, (colloquial) muṭṭawwaʿīn) volunteer, person willingly offering (himself or his services for the furtherance of good), active participle of iṭṭawwaʿa, euphonic form of taṭawwaʿa to perform good deeds beyond those prescribed by Islamic law: see further (but with a different derivation) Encycl. Islam (new ed. vii, 1993) at Mutaṭawwiʿa, Muṭṭawwiʿa.