input/output n 1. (Computer Science) the data or information that is passed into or out of a computer. Abbreviation: I/O 2. (Computer Science) (modifier) concerned with or relating to such passage of data or information Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014in?put/out?put (??n?p?t?a?t?p?t) n. the combination of devices, channels, and techniques controlling the transfer of information between a CPU and its peripherals. Abbr.: I/O [1910?15] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.