Lexical semantics is a subfield of linguistics that studies the meaning of lexical items. It investigates the nature of word meaning, including how individual word senses are structured, how words relate to concepts and external reality, and the systematic relationships between lexical items within the vocabulary of a language. Key characteristics include the analysis of polysemy, homonymy, and sense relations such as synonymy, antonymy, and hyponymy, often involving the development of formal or computational models of the lexicon. Its significance lies in providing foundational insights into the linguistic encoding of meaning, contributing to theories of language and cognition, and supporting applications in computational linguistics and natural language processing.