cough drop vs pastille

cough drop and pastille both are nouns.

Word	Noun	Adjective	Verb	Adverb
cough drop	Yes	No	No	No
pastille	Yes	No	No	No

As nouns, cough drop and pastille are synonyms defined as:

Other synonyms of cough drop include pastil, troche.

cough drop (noun)	pastille (noun)
a medicated lozenge used to soothe the throat	a medicated lozenge used to soothe the throat