The Collaborative International Dictionary of English v.0.48:

Mac \Mac\ prop. n.
   Shortened form of Macintosh, a brand name for a personal
   computer; as, the latest Mac has great new features.
   [PJC]

The Collaborative International Dictionary of English v.0.48:

Macintosh \Mac"in*tosh\, n.
   1. Same as Mackintosh.
      [1913 Webster]

   2. [Trademark.] (Computers) A brand of personal computer
      featuring an integrated system in which the hardware and
      system-operating software were designed by or under the
      control of a single company, the Apple Computer
      Corporation; among personal computers, distinguished from
      the IBM-compatible or Intel-based series of computers.
      [PJC]

WordNet (r) 3.0 (2006):

macintosh
    n 1: a lightweight waterproof (usually rubberized) fabric [syn:
         mackintosh, macintosh]
    2: a waterproof raincoat made of rubberized fabric [syn:
       macintosh, mackintosh, mac, mack]

The Free On-line Dictionary of Computing (30 December 2018):

Macintosh
Apple Macintosh
beige toaster

    One of the trademark/brand names that Apple Inc
   use for their Mac family of personal computers.

   (2009-05-05)