The term 'Wahhabi' is an eponym, formed from the name of the 18th-century Arabian religious reformer Muhammad ibn Abd al-Wahhab (c. 1703–1792), with the addition of the English adjectival suffix '-i'. This suffix, borrowed via Latin '-ius' and Greek '-ios', is commonly used in English to form adjectives and nouns denoting affiliation or origin, as in 'Pakistani' or 'Iraqi'. The name 'al-Wahhab' itself is an Arabic epithet meaning "the Bestower," one of the names of God in Islam, which his ancestors adopted. The term was initially used by opponents of the movement but later became a standard, though sometimes contested, external label for its adherents and their doctrine.

The word is a proper noun derived from the name of its founder, Muhammad ibn Abd al-Wahhab. It is not productively formed from smaller, independent English morphemes.