ataractic agent vs tranquillizer

ataractic agent and tranquillizer both are nouns.

Word	Noun	Adjective	Verb	Adverb
ataractic agent	Yes	No	No	No
tranquillizer	Yes	No	No	No

As nouns, ataractic agent and tranquillizer are synonyms defined as:

ataractic agent and tranquillizer: a drug used to reduce stress or tension without reducing mental clarity

Other synonyms of ataractic agent include antianxiety agent, ataractic, ataractic drug, tranquilizer, tranquilliser.

ataractic agent (noun)	tranquillizer (noun)
a drug used to reduce stress or tension without reducing mental clarity	a drug used to reduce stress or tension without reducing mental clarity