automated teller machine vs automated teller

automated teller machine and automated teller both are nouns.

Word	Noun	Adjective	Verb	Adverb
automated teller machine	Yes	No	No	No
automated teller	Yes	No	No	No

As nouns, automated teller machine and automated teller are synonyms defined as:

automated teller machine and automated teller: an unattended machine (outside some banks) that dispenses money when a personal coded card is used

Other synonyms of automated teller machine include ATM, automatic teller, automatic teller machine, cash dispenser, cash machine.

automated teller machine (noun)	automated teller (noun)
an unattended machine (outside some banks) that dispenses money when a personal coded card is used	an unattended machine (outside some banks) that dispenses money when a personal coded card is used