tangent (English)
Where does "tangent" come from?
The English word tangent was borrowed from Latin 'tangentem', the accusative form of 'tangēns', meaning touching[1]. This Latin participle comes from the verb 'tangō' meaning to touch[1], which stems from Proto-Italic '*tangō'[1][2]. Ultimately, these forms trace back to the Proto-Indo-European root '*teh₂g-' meaning to touch[1][2]. The term originates from the mathematical phrase 'līnea tangēns', meaning a touching line[1].
Open questions
- The Proto-Italic form '*tangō' is reconstructed from Proto-Indo-European with a nasal infix. [2]
Full etymology tree
- tangent (English), 'Touching a curve at a single point but not crossing it at that point.'
- borrowed tangentem (Latin), 'accusative masculine/feminine singular of tangēns'
- inherited tangens (Latin), 'touching, grasping'
- derived tango (Latin), 'to touch, grasp'
- inherited *tangō (Proto-Italic), 'to touch'
- derived *teh₂g- (Proto-Indo-European), 'to touch'
- inherited *tangō (Proto-Italic), 'to touch'
- derived tango (Latin), 'to touch, grasp'
- inherited tangens (Latin), 'touching, grasping'
- borrowed tangentem (Latin), 'accusative masculine/feminine singular of tangēns'
Ancestors
- *teh₂g- (Proto-Indo-European)
- tangentem (Latin)
- *tangō (Proto-Italic)
Cognates and doublets
- þaccian (Old English)
Descendants and derived words
- tangently (English)
Sources
- tangent (English) - Wiktionary
- tangō (Proto-Italic) - Wiktionary
- tangens (Latin) - Wiktionary
- linea (Latin) - Wiktionary
Updated August 2026
Etymology data from Wiktionary, CC BY-SA 4.0 · About Miraris