automatic teller machine vs automatic teller

automatic teller machine and automatic teller both are nouns.

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

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

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

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

automatic teller machine (noun)	automatic 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