cimetidine vs antacid

cimetidine and antacid both are nouns.

Word	Noun	Adjective	Verb	Adverb
cimetidine	Yes	No	No	No
antacid	Yes	Yes	No	No

As nouns, antacid is a hypernym of cimetidine; that is, antacid is a word with a broader meaning than cimetidine:

cimetidine: a drug (trade name Tagamet) used to treat peptic ulcers by decreasing the secretion of stomach acid
antacid: an agent that counteracts or neutralizes acidity (especially in the stomach)

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

cimetidine (noun)	antacid (noun)
a drug (trade name Tagamet) used to treat peptic ulcers by decreasing the secretion of stomach acid	an agent that counteracts or neutralizes acidity (especially in the stomach)

cimetidine (adjective)	antacid (adjective)
	acting to neutralize acid (especially in the stomach)