extortionist vs blackmailer

extortionist and blackmailer both are nouns.

Word	Noun	Adjective	Verb	Adverb
extortionist	Yes	No	No	No
blackmailer	Yes	No	No	No

As nouns, extortionist and blackmailer are synonyms defined as:

extortionist and blackmailer: a criminal who extorts money from someone by threatening to expose embarrassing information about them

Other synonyms of extortionist include extortioner.

extortionist (noun)	blackmailer (noun)
a criminal who extorts money from someone by threatening to expose embarrassing information about them	a criminal who extorts money from someone by threatening to expose embarrassing information about them