Lemma (linguistics)

A lemma is a conventional citation form used to represent a lexical entry or a set of related grammatical forms. It differs from a lexeme, the abstract vocabulary item being represented, and from an arbitrary truncation of a word's spelling. The convention is language-specific.^[ref]

In a simple English analysis, walks, walked and walking can be assigned the lemma walk. The Universal Dependencies guidelines also distinguish inflection from derivational morphology: organizations has citation form organization, not organize or organ.

Context can be needed before the citation form is chosen. The spelling saw can name a tool or occur as a past form of see; a process that uses spelling alone cannot settle every such ambiguity. Recording the part of speech, intended word sense and the original occurrence makes a text corpus analysis more reproducible than retaining only the normalized label.