Hyponymy and hypernymy
（重定向自Hyponym）
In linguistics, a hyponym (from Greek hupó, "under" and ónoma, "name") is a word or phrase whose semantic field is included within that of another word, its hyperonym or hypernym (from Greek hupér, "over" and ónoma, "name") . In simpler terms, a hyponym shares a type-of relationship with its hypernym. For example, pigeon, crow, eagle and seagull are all hyponyms of bird (their hypernym); which, in turn, is a hyponym of animal.