{{Short description|Unit of lexical meaning}} {{For|its use in the context of computer science|Lexeme (computer science)}}
A '''lexeme''' ({{IPAc-en|audio=En-us-lexeme.ogg|ˈ|l|ɛ|k|s|iː|m}}) is a unit of lexical meaning that underlies a set of words that are related through inflection. It is a basic abstract unit of meaning,<ref>''The Cambridge Encyclopedia of The English Language''. David Crystal. Cambridge: Cambridge University Press, 1995. p. 118. {{ISBN|0521401798}}.</ref> a unit of morphological analysis in linguistics that roughly corresponds to a set of forms taken by a single root word. For example, in the English language, ''run'', ''runs'', ''ran'' and ''running'' are forms of the same lexeme, which can be represented as <span style="font-variant:small-caps; text-transform:lowercase;">RUN</span>.{{NoteTag |1 = <span style="font-variant:small-caps; text-transform:lowercase;">RUN</span> is here intended to display in small caps. Software limitations may result in its display either in full-sized capitals (RUN) or in full-sized capitals of a smaller font. Either is regarded as an acceptable substitute for genuine small caps.}}
One form, the lemma (or citation form), is chosen by convention as the canonical form of a lexeme. The lemma is the form used in dictionaries as an entry's headword. Other forms of a lexeme are often listed later in the entry if they are uncommon or irregularly inflected.
== Description == The notion of the lexeme is central to morphology,<ref name="bonamietal">{{Cite book | veditors = Bonami O, Boyé G, Dal G, Giraudo H, Namer F | title = The lexeme in descriptive and theoretical morphology | location = Berlin | publisher = Language Science Press | year = 2018 | format = pdf | url = http://langsci-press.org/catalog/book/165 | doi = 10.5281/zenodo.1402520 | doi-access=free | isbn = 978-3-96110-110-8 | last1 = Bonami | first1 = Olivier | last2 = Boyé | first2 = Gilles | last3 = Dal | first3 = Georgette | last4 = Giraudo | first4 = Hélène | last5 = Namer | first5 = Fiammetta }} </ref> the basis for defining other concepts in that field. For example, the difference between inflection and derivation can be stated in terms of lexemes: * Inflectional rules relate a lexeme to its forms. * Derivational rules relate a lexeme to another lexeme.
A lexeme belongs to a particular syntactic category, has a certain meaning (semantic value), and in inflecting languages, has a corresponding inflectional paradigm. That is, a lexeme in many languages will have many different forms. For example, the lexeme <span style="font-variant:small-caps; text-transform:lowercase;">RUN</span> has a present third person singular form ''runs'', a present non-third-person singular form ''run'' (which also functions as the past participle and non-finite form), a past form ''ran'', and a present participle ''running''. (It does not include ''runner, runners, runnable'' etc.) The use of the forms of a lexeme is governed by rules of grammar. In the case of English verbs such as <span style="font-variant:small-caps; text-transform:lowercase;">RUN</span>, they include subject–verb agreement and compound tense rules, which determine the form of a verb that can be used in a given sentence.
In many formal theories of language, lexemes have subcategorization frames to account for the number and types of complements. They occur within sentences and other syntactic structures.
== Decomposition == A language's lexemes are often composed of smaller units with individual meaning called morphemes, according to root morpheme + derivational morphemes + affix (not necessarily in that order), where: * The root morpheme is the primary lexical unit of a word, which carries the most significant aspects of semantic content and cannot be reduced to smaller constituents.<ref>{{cite web |url = https://glossary.sil.org/term/root |title = SIL Glossary of Linguistic Terms: What is a Root? |website = Sil.org |date = 3 December 2015 |access-date=2021-05-14}}</ref> * The derivational morphemes carry only derivational information.<ref>{{cite web |url = https://glossary.sil.org/term/derivational-affix |title = SIL Glossary of Linguistic Terms: What is a Derivational Affix? |website = Sil.org |date = 3 December 2015 |access-date=2021-05-14}}</ref> * The affix is composed of all inflectional morphemes, and carries only inflectional information.<ref>{{cite web |url = https://glossary.sil.org/term/inflectional-affix |title = SIL Glossary of Linguistic Terms: What is an Inflectional Affix? |website = Sil.org |date = 3 December 2015 |access-date=2021-05-14}}</ref>
The compound root morpheme + derivational morphemes is often called the stem.<ref>{{cite web |url = https://glossary.sil.org/term/stem |title = SIL Glossary of Linguistic Terms: What is a Stem? |website = Sil.org |date = 3 December 2015 |access-date=2021-05-14}}</ref> The decomposition stem + desinence can then be used to study inflection.
== See also == {{Portal|Linguistics|Language}} * Ending (linguistics) * Inflection * Lemma * Lexicon * Lexical item * Lexical word vs. grammatical word * Marker (linguistics) * Multiword expression * Null morpheme * Root (linguistics) * Stem * Syntagma (linguistics) * Word family
== Notes == {{NoteFoot}}
== References == {{Reflist}}
== External links == * {{Wiktionary-inline|lexeme}}
{{-}} {{Lexicology}} {{Lexicography}}
{{authority control}}
Category:Lexical units Category:Linguistics terminology