major tranquilizer vs ataractic

major tranquilizer and ataractic both are nouns.

Word	Noun	Adjective	Verb	Adverb
major tranquilizer	Yes	No	No	No
ataractic	Yes	Yes	No	No

As nouns, ataractic is a hypernym of major tranquilizer; that is, ataractic is a word with a broader meaning than major tranquilizer:

major tranquilizer: tranquilizer used to treat psychotic conditions when a calming effect is desired
ataractic: a drug used to reduce stress or tension without reducing mental clarity

Other hypernyms of major tranquilizer include antianxiety agent, ataractic agent, ataractic drug, tranquilizer, tranquilliser, tranquillizer.

major tranquilizer (noun)	ataractic (noun)
tranquilizer used to treat psychotic conditions when a calming effect is desired	a drug used to reduce stress or tension without reducing mental clarity

major tranquilizer (adjective)	ataractic (adjective)
	tending to soothe or tranquilize