meclizine vs antihistamine

meclizine and antihistamine both are nouns.

Word	Noun	Adjective	Verb	Adverb
meclizine	Yes	No	No	No
antihistamine	Yes	No	No	No

As nouns, antihistamine is a hypernym of meclizine; that is, antihistamine is a word with a broader meaning than meclizine:

meclizine: an antihistamine (trade name Antivert) used to treat or prevent motion sickness
antihistamine: a medicine used to treat allergies and hypersensitive reactions and colds; works by counteracting the effects of histamine on a receptor site

meclizine (noun)	antihistamine (noun)
an antihistamine (trade name Antivert) used to treat or prevent motion sickness	a medicine used to treat allergies and hypersensitive reactions and colds; works by counteracting the effects of histamine on a receptor site