Atm Definition

ātēĕm
abbreviation
Atmosphere.
Webster's New World
Asynchronous transfer mode.
Webster's New World

Atmosphere (as a unit of pressure)

Wiktionary
(Internet slang) Initialism of at the moment.
Wiktionary
noun
An unattended electronic machine in a public place, connected to a data system and related equipment and activated by a bank customer to obtain cash withdrawals and other banking services.
American Heritage
A computer terminal that allows a bank customer to deposit, withdraw, or transfer funds automatically.
Webster's New World