complex (English)
Where does "complex" come from?
The word complex traces its roots back to the Proto-Indo-European *pleḱ-, meaning to weave or fold. It evolved into the Latin complexus, meaning to entwine or encircle, before passing into French and eventually entering English. Over time, the literal sense of objects being woven together shifted to describe things that are complicated or made of multiple interconnected parts.
Full etymology tree
- complex (English), 'Made up of multiple parts; composite; not simple.'
- borrowed complexe (French), 'complex, not simple'
- inherited complexus (Latin), 'embraced'
- deverbal complector (Latin), 'to embrace or hug'
- compound com- (Latin), 'allomorph of con-'
- inherited cum (Latin), 'with, along with'
- compound plectō (Latin), 'to plait, weave, braid'
- inherited *plektō (Proto-Italic)
- inherited *pleḱ- (Proto-Indo-European), 'to fold, plait, weave'
- derived *pel- (Proto-Indo-European), 'to cover, to wrap'
- inherited *pleḱ- (Proto-Indo-European), 'to fold, plait, weave'
- inherited *plektō (Proto-Italic)
- compound com- (Latin), 'allomorph of con-'
- deverbal complector (Latin), 'to embrace or hug'
- inherited complexus (Latin), 'embraced'
- borrowed complexe (French), 'complex, not simple'
Direct ancestors
- pleḱ- (Proto-Indo-European)
- complexe (French)
- complexus (Latin)
- com- (English)
- -plex (English)
- complexus (English)
Updated July 2026
Etymology data from Wiktionary, CC BY-SA 4.0 · About Miraris