cohyponim

Cohyponim (also spelled co-hyponym or cohyponym) is a linguistic term for two or more lexical items that are hyponyms of the same hypernym. As hyponyms, each item denotes a specific kind within a broader category. Because they share the same hypernym, these hyponyms are siblings in a semantic hierarchy: they are cohyponyms.

Common examples include car and bicycle under vehicle, or apple and orange under fruit. The key relationship is that each item falls under the same broad class, yet they refer to different specific instances within that class. The hypernym can be a broad term like animal or a more specific one like pet, depending on how the taxonomy is defined.

In linguistic analysis and natural language processing, identifying cohyponyms helps describe semantic fields, organize thesauri, and support tasks such as word-sense disambiguation and clustering of related terms. In lexical databases like WordNet, the concept is reflected by sets of hyponyms that share a common parent synset, illustrating their parallel standing within a hierarchical structure.

Notes on terminology: the form and spelling vary in sources, with cohyponim, cohyponym, and co-hyponym all encountered. The underlying idea remains the same: a group of words that are all more specific than a single broader term and occupy the same level in the semantic hierarchy.