markup language vs nomenclature

markup language and nomenclature both are nouns.

Word	Noun	Adjective	Verb	Adverb
markup language	Yes	No	No	No
nomenclature	Yes	No	No	No

As nouns, nomenclature is a hypernym of markup language; that is, nomenclature is a word with a broader meaning than markup language:

markup language: a set of symbols and rules for their use when doing a markup of a document
nomenclature: a system of words used to name things in a particular discipline

Other hypernyms of markup language include language, terminology.

markup language (noun)	nomenclature (noun)
a set of symbols and rules for their use when doing a markup of a document	a system of words used to name things in a particular discipline