What does expert mean?
An expert is a person who possesses comprehensive, authoritative knowledge or highly developed skill in a particular field, whether that field is academic, professional, artistic, or practical. The term implies more than casual familiarity: an expert's judgment is trusted because it rests on extensive training, study, or hands-on experience, and their opinions often carry special weight — as in an 'expert witness' in court or an 'expert review' of a document. The word can also function as an adjective describing something done with such mastery, as in expert craftsmanship. Its synonyms range from the neutral 'specialist' and 'authority' to terms like 'connoisseur', which suggests refined taste rather than technical command. Because modern life increasingly relies on specialized knowledge, calling someone an expert is a meaningful claim about competence and credibility, and the word remains central to discussions of trust, authority, and professional standards.
A person who has comprehensive and authoritative knowledge of, or skill in, a particular area.
"Experts disagree on how best to treat the condition."
Often followed by 'on', 'in', or 'at' to specify the field: 'an expert on birds', 'an expert in finance'.
Having or demonstrating great skill or specialized knowledge; done with such skill.
"The restoration required expert handling of delicate materials."
Frequently appears in fixed phrases such as 'expert witness' and 'expert opinion', where the adjective carries legal weight.
Standard regular plural; commonly used when referring to panels or groups of specialists, e.g., 'a panel of experts'.
"The report drew on experts from three continents."
An 'expert' is literally someone who has been 'tried' — the word comes from the Latin experiri, meaning to put to the test.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of expert
The English word 'expert' comes from the Latin 'expertus', the past participle of 'experiri', meaning 'to try, test, or attempt'. It entered English in the late Middle Ages, initially as an adjective meaning experienced or proven through trial, before developing its familiar noun sense of a person skilled through tested experience. The same Latin root gives us 'experience' and 'experiment', and its Greek cousin underlies 'empirical'.
Related word forms
How expert is actually used
As an adjective, 'expert' means having or involving authoritative knowledge (e.g., 'expert witness', 'expert level'), though it functions primarily as a noun. It carries a connotation of formal recognition or demonstrated mastery rather than mere self-assessment.
Easily confused with expert
'Expert' refers to the person who possesses the knowledge, while 'expertise' refers to the skill or specialized knowledge itself.