antiacid vs antacid

antiacid and antacid both are nouns.

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

As nouns, antiacid and antacid are synonyms defined as:

antiacid and antacid: an agent that counteracts or neutralizes acidity (especially in the stomach)

Other synonyms of antiacid include alkaliser, alkalizer, gastric antacid.

antiacid (noun)	antacid (noun)
an agent that counteracts or neutralizes acidity (especially in the stomach)	an agent that counteracts or neutralizes acidity (especially in the stomach)

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