ATM (Noun) — A means of digital communications that is capable of very high speeds; suitable for transmission of images, voice or video as well as data. ex. "ATM is used for both LAN and WAN"
ATM (Noun) — An unattended machine (outside some banks) that dispenses money when a personal coded card is used.
ATM (Noun) — A unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade.