[em-es daws, -dos]
an operating system for personal computers, originally developed by Microsoft for IBM computers.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
trademark computing a type of disk operating system
Word Origin for MS-DOS
C20: from M (icro) s (oft), the company that developed it, + DOS
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012