hyponyme

Hyponymy is a semantic relation between words in which the meaning of one word, the hyponym, is included within the meaning of another word, the hypernym. The hyponym denotes a more specific kind or instance of the hypernym. For example, dog is a hyponym of animal, and poodle is a hyponym of dog (and thus of animal by transitivity). The term is part of lexical semantics and is used to describe hierarchical classifications in language.

Properties of the relation include that it is asymmetric: if X is a hyponym of Y, Y is not a hyponym of X. It is transitive: if A is a hyponym of B and B is a hyponym of C, then A is a hyponym of C. Hyponymy can extend across different domains and parts of speech, though the boundary definitions may vary with context. A single word may have multiple hypernyms in a broader sense, and hyponym sets can be large and overlapping. Co-hyponyms are words that share the same hypernym but are not hyponyms of one another (for example, dog and cat under animal).

Applications of hyponymy include the construction of lexical hierarchies, thesauri, and ontologies. It is used in information retrieval, word sense disambiguation, and various natural language processing tasks such as taxonomy induction and semantic search. The concept is a foundational element in how languages organize and relate categories of objects and ideas.