In linguistics, an agent noun (in Latin, nomen agentis) is a word that is derived from another word denoting an action, and that identifies an entity that does that action.^[1] For example, driver is an agent noun formed from the verb drive.^[2]

Usually, derived in the above definition has the strict sense attached to it in morphology, that is the derivation takes as an input a lexeme (an abstract unit of morphological analysis) and produces a new lexeme. However, the classification of morphemes into derivational morphemes (see word formation) and inflectional ones is not generally a straightforward theoretical question, and different authors can make different decisions as to the general theoretical principles of the classification as well as to the actual classification of morphemes presented in a grammar of some language (for example, of the agent noun-forming morpheme).

An agentive suffix or agentive prefix is commonly used to form an agent noun from a verb. Examples:

• English: -er, -or, -ian, -ist
• Basque: -le (ikasle 'student' from ikasi 'learn')
• Chinese: ⋯者 (-zhě)
• Dutch: -er, -ende, -or, -iet, -ant, -aar
• Finnish: -ja/-jä (puhua 'speak', puhuja 'speaker'; lyödä 'hit', lyöjä 'hitter'); -uri (borrowed from '-or'/'er', probably via German)
• French: -(t)eur (m.); -(t)eure,^[3] -(t)euse, -trice, -iste (f.)
• Georgian: მე- ... -ე (me- ... -e), as in მებაღე (mebaghe 'gardener') from ბაღი (baghi 'garden'); otherwise the nominalization of the present participle (formed with many possible circumfixes) may occur.^[4]
• German: -er, -ler, -ner, -or, -ör, -ist, -it, -ite, -ant, -ent (may be compounded with the feminine ending -in)
• Greek: -ήρ, -τήρ
• Hungarian: no specific agentive suffix, the nominalization of present participle (suffix: -ó/-ő, according to vowel harmony) is used instead; examples: dolgozó ('worker'), szerelő ('repairman'), vezető ('leader', 'driver', 'electrical conductor')
• Irish: -óir (broad), -eoir (slender), -aí (broad), -í (slender)
• Khasi: prefix nong- or myn-, for example shad 'to dance', nongshad 'dancer'; tuh 'to steal', myntuh 'thief'
• Latin: -tor (m.) / -trix (f.) / -trum (n.) / -torius, -a, -um (adj.) as in arator / aratrix / aratrum / aratorius; -sor (m.) / -strix (f.) / -strum (n.) / -sorius, -a, -um (adj.) as in assessor / assestrix / *assestrum / assessorius; see also: -ens
• Maori: kai-
• Persian: ـنده (-ande): from present roots; as in گوینده (gūyande; 'speaker') from گفتن، گوی- (goftan, gūy-; to speak) / ـار (-ār) : from past roots; as in خواستار (x^wāstār; 'wanter') from خواستن، خواه- (x^wāstan, x^wāh-; 'to want'). / ـگر (-gar): from nouns; as in کارگر (kārgar; 'worker') from کار (kār; 'work').^[5]
• Polish: see table
• Quechua: -q (pukllay 'to play', pukllaq 'player')
• Russian: -чик or -ник (m.) / -чица or -ница (f.) as in ученик 'student'; -тель (m.) / -тельница (f.) as in учитель 'teacher'^[6]
• Spanish: -dor(a), -ero(a), -ista, -ario(a)
• Turkish: -ci (çiçekçi 'florist' from çiçek 'flower')
• Welsh: -wr (m.), -ores (f.)

• Agent (grammar)
• Nominalization

Look up agent noun, -er, -ist, or -or in Wiktionary, the free dictionary.

• Maria Wojtyła-Świerzowska, Prasłowiańskie nomen agentis ("Protoslavic Nomen Agentis"), Wrocław, 1975