bank clerk vs teller

bank clerk and teller both are nouns.

Word	Noun	Adjective	Verb	Adverb
bank clerk	Yes	No	No	No
teller	Yes	No	No	No

As nouns, bank clerk and teller are synonyms defined as:

bank clerk and teller: an employee of a bank who receives and pays out money

Other synonyms of bank clerk include cashier.

bank clerk (noun)	teller (noun)
an employee of a bank who receives and pays out money	an employee of a bank who receives and pays out money
	an official appointed to count the votes (especially in legislative assembly)
	someone who tells a story