expert (English)
Where does "expert" come from?
The English noun 'expert' came through Middle English from an Old French word meaning 'experienced'[1]. That term traces back to Latin 'expertus', the participle of 'experior', meaning 'to try, attempt, or experience'[1][2]. Underlying this Latin verb is a prefix combined with the base root meaning to risk or go through, which ultimately derives from the Proto-Indo-European root '*per-'[3].
Open questions
- Linguist Michiel de Vaan disputes the standard derivation from Proto-Indo-European '*per-', proposing instead an origin in Latin 'pario' from Proto-Indo-European '*perh3-'. [3]
- The intermediate Latin verb form '*perior' is an unattested, reconstructed stage. [3]
Full etymology tree
- expert (English), 'A person with extensive knowledge or ability in a given subject.'
- inherited (Middle English)
- derived (Old French)
- derived expertus (Latin), 'experienced; having experienced'
- deverbal experior (Latin), 'to attempt, to try; to test, to put to the test, to find out, to prove; therefore, to make trial of a person or thing'
- prefix ex- (Latin), 'out, away'
- affix *perior (Latin)
- deverbal experior (Latin), 'to attempt, to try; to test, to put to the test, to find out, to prove; therefore, to make trial of a person or thing'
- derived expertus (Latin), 'experienced; having experienced'
- derived (Old French)
- inherited (Middle English)
Ancestors
- *per- (Proto-Indo-European)
- expertus (Latin)
Sources
Updated October 2026
Etymology data from Wiktionary, CC BY-SA 4.0 · About Miraris