#1 atm n. [standard atmosphere, atmosphere, standard pressure] a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade. wn
#2 atm n. [asynchronous transfer mode, ATM] a means of digital communications that is capable of very high speeds; suitable for transmission of images or voice or video as well as data; "ATM is used for both LAN and WAN". wn
#3 atm n. [cash machine, cash dispenser, automated teller machine, automatic teller machine, automated teller, automatic teller, ATM] an unattended machine (outside some banks) that dispenses money when a personal coded card is used. wn
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