ataractic agent vs tranquilliser

ataractic agent and tranquilliser both are nouns.

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

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

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

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

ataractic agent (noun)	tranquilliser (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