Zantac vs antiacid

Zantac and antiacid both are nouns.

Word	Noun	Adjective	Verb	Adverb
Zantac	Yes	No	No	No
antiacid	Yes	No	No	No

As nouns, antiacid is a hypernym of Zantac; that is, antiacid is a word with a broader meaning than Zantac:

Zantac: a histamine blocker and antacid (trade name Zantac) used to treat peptic ulcers and gastritis and esophageal reflux
antiacid: an agent that counteracts or neutralizes acidity (especially in the stomach)

Other hypernyms of Zantac include histamine blocker, alkaliser, alkalizer, antacid, gastric antacid.

Zantac (noun)	antiacid (noun)
a histamine blocker and antacid (trade name Zantac) used to treat peptic ulcers and gastritis and esophageal reflux	an agent that counteracts or neutralizes acidity (especially in the stomach)