SIM Card n acronym for (Telecommunications) subscriber identity module card: a small card used in a mobile phone to store data about the network, telephone number, etc Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014