A
lexeme is a unit of lexical meaning that exists regardless of the number of inflectional endings it may have or the number of words it may contain. It is a basic unit of meaning, and the headwords of a dictionary are all lexemes. Put more technically, a lexeme is an abstract
unit of
morphological analysis in
linguistics, that roughly corresponds to a set of forms taken by a single
word. For example, in the
English language,
run,
runs,
ran and
running are forms of the same lexeme, conventionally written as
RUN. A related concept is the
lemma (or citation form), which is a particular form of a lexeme that is chosen by convention to represent a canonical form of a lexeme.
Lemmas, being a subset of lexemes, are likewise used in dictionaries as the
headwords, and other forms of a lexeme are often listed later in the entry if they are not common
conjugations of that word.