sycophant vs flatterer

sycophant and flatterer both are nouns.

Word	Noun	Adjective	Verb	Adverb
sycophant	Yes	No	No	No
flatterer	Yes	No	No	No

As nouns, flatterer is a hypernym of sycophant; that is, flatterer is a word with a broader meaning than sycophant:

sycophant: a person who tries to please someone in order to gain a personal advantage
flatterer: a person who uses flattery

Other hypernyms of sycophant include adulator.

sycophant (noun)	flatterer (noun)
a person who tries to please someone in order to gain a personal advantage	a person who uses flattery