IM
noun /ˌaɪ ˈem/
/ˌaɪ ˈem/
(informal)- (also instant message)[countable, uncountable] a written message sent using a system on the internet that allows people to communicate with each other very quickly; the system of sending these messages
- (also instant messaging)[uncountable] a system on the internet that allows people to exchange written messages with each other very quickly