hyponymy n.

word-forming element meaning "under, beneath; less, less than" (in chemistry, indicating a lesser oxidation), from Greek hypo (prep. and adverb) "under, beneath; up from under; toward and under (i.e. into)," from PIE root *upo "under."

Proto-Indo-European root meaning "name."

It forms all or part of: acronym; allonym; ananym; anonymous; antonomasia; antonym; binomial; caconym; cognomen; denominate; eponym; eponymous; heteronym; homonym; homonymous; hyponymy; ignominious; ignominy; innominable; Jerome; matronymic; metonymy; metronymic; misnomer; moniker; name; nomenclature; nominal; nominate; noun; onomastic; onomatopoeia; paronomasia; paronym; patronym; patronymic; praenomen; pronoun; pseudonym; renown; synonym; synonymy; synonymous; toponym.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit nama; Avestan nama; Greek onoma, onyma; Latin nomen; Old Church Slavonic ime, genitive imene; Russian imya; Old Irish ainm; Old Welsh anu "name;" Old English nama, noma, Old High German namo, Old Norse nafn, Gothic namo "name."