incompatible vs antacid

incompatible is not a noun while antacid is a noun.

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

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

incompatible (adjective)	antacid (adjective)
used especially of drugs or muscles that counteract or neutralize each other's effect	acting to neutralize acid (especially in the stomach)
not compatible
incapable of being used with or connected to other devices or components without modification
not suitable to your tastes or needs
of words so related that one contrasts with the other
used especially of solids or solutions; incapable of blending into a stable homogeneous mixture
not in keeping with what is correct or proper
not compatible with other facts
not easy to combine harmoniously