In
morphology and
lexicography, a
lemma (plural
lemmas or
lemmata) is the
canonical form,
dictionary form, or
citation form of a set of
words (
headword). In
English, for example,
run,
runs,
ran and
running are forms of the same
lexeme, with
run as the lemma.
Lexeme, in this context, refers to the set of all the forms that have the same meaning, and
lemma refers to the particular form that is chosen by convention to represent the lexeme. In lexicography, this unit is usually also the
citation form or
headword by which it is indexed. Lemmas have special significance in highly
inflected languages such as Arabic,
Turkish and
Russian. The process of determining the
lemma for a given word is called
lemmatisation. The lemma can be viewed as the chief of the
principal parts, although lemmatisation is at least partly arbitrary.