obtuse (English)
Where does "obtuse" come from?
The word obtuse traces its roots back to the Proto-Indo-European root *(s)tewd-, meaning to hit or push. It eventually entered Latin as obtūsus, describing something that had been beaten or battered until it became blunt or dull. Over time, this evolved from a physical description of sharpness into its current English usage, referring to both geometric angles and intellectual sluggishness.
Full etymology tree
- obtuse (English), 'Blunt; not sharp, pointed, or acute in form.'
- inherited obtuse (Middle English)
- learned borrowing obtusus (Latin), 'struck, beaten, buffeted'
- deverbal obtundere (Latin), 'second-person singular future passive indicative of obtundō'
- compound ob- (Latin), 'towards; against'
- compound tundō (Latin), 'to beat, strike, buffet'
- inherited *tundō (Proto-Italic), 'to beat, strike'
- inherited *(s)tunédti (Proto-Indo-European), 'to be pushing, hitting'
- derived *(s)tewd- (Proto-Indo-European), 'to push, to hit'
- derived *(s)tew- (Proto-Indo-European), 'to push, to hit'
- derived *(s)tewd- (Proto-Indo-European), 'to push, to hit'
- inherited *(s)tunédti (Proto-Indo-European), 'to be pushing, hitting'
- inherited *tundō (Proto-Italic), 'to beat, strike'
- deverbal obtundere (Latin), 'second-person singular future passive indicative of obtundō'
- learned borrowing obtusus (Latin), 'struck, beaten, buffeted'
- inherited obtuse (Middle English)
Direct ancestors
Updated June 2026
Etymology data from Wiktionary, CC BY-SA 4.0 · About Miraris