cdrom

from The Collaborative International Dictionary of English v.0.48

CD-ROM \CD-ROM\ n.
   a compact disk that is used with a computer (rather than with
   an audio system); a large amount of digital information can
   be stored and accessed but it cannot be altered by the user.

   Syn: compact disc read-only memory.
        [WordNet 1.5]

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

CDROM
       Compact Disk - Read Only Memory (CD, ROM), "CD-ROM"