A lexical chain is a sequence of related words in writing, spanning short (adjacent words or sentences) or long distances (entire text). A chain is independent of the grammatical structure of the text and in effect it is a list of words that captures a portion of the cohesive structure of the text. A lexical chain can provide a context for the resolution of an ambiguous term and enable identification of the concept that the term represents.
Examples of lexical chains are the following:
Rome → capital → city → inhabitant
Wikipedia → resource → web
References
Lexical chain Wikipedia(Text) CC BY-SA