megabyte

noun2

1. •
   One million (10⁶, or 1,000,000) bytes or 1,000 kilobytes.

   • The IBM 2301 Drum Storage (Figure 20) provides random access storage of approximately 4 million bytes at a data rate of 1.2 megabytes per second. — 1964
2. •
   (informal) A mebibyte.

   • One megabyte is 1,048,576 bytes. One megahertz, however is a million Hertz. — 2003