'antitangent' originates from a Modern compound formed from Greek 'anti-' (from Greek ἀντί) and Latin 'tangens' (present participle of Latin 'tangere'), where 'anti-' meant 'against, opposite' and 'tangere' meant 'to touch'.

'antitangent' was formed in early modern mathematical English/Latin as a compound of 'anti-' + 'tangent' and appeared in 17th–19th century works to denote a quantity related to the tangent; over time the term was largely replaced by 'arctangent' and fell into rare or obsolete usage.

Initially formed to express an idea 'opposite (or complementary) to the tangent', its use shifted in some historical sources to denote the inverse tangent (arctangent); in modern usage the term is now rare and 'arctangent' is standard.