Noun

1. One million bytes. SI Symbol: MB
2. 1,048,576 bytes; a mebibyte. Frequently abbreviated MB.
   • 2003, Michael Meyers, Managing and Troubleshooting PCs, page 933

     One megabyte is 1,048,576 bytes. One megahertz, however is a million Hertz.

   • 2004, Kerry Cox & Christopher Gerg, Managing Security with Snort and IDS Tools, page 92

     Defaults to 2 megabytes (2,097,152 bytes).

   • 2006, Eriq Oliver Neale, Microsoft Small Business Server 2003 Unleashed, page 290

     By default, each log file [...] is exactly 5 megabytes (5,242,880 bytes) in size.