pretender vs impostor

pretender and impostor both are nouns.

Word	Noun	Adjective	Verb	Adverb
pretender	Yes	No	No	No
impostor	Yes	No	No	No

As nouns, pretender and impostor are synonyms defined as:

Other synonyms of pretender include fake, faker, fraud, imposter, pseud, pseudo, role player, sham, shammer.

pretender (noun)	impostor (noun)
a person who makes deceitful pretenses	a person who makes deceitful pretenses
a person who professes beliefs and opinions that he or she does not hold in order to conceal his or her real feelings or motives