WordNet (r) 3.0 (2006):

anonymous ftp
    n 1: a common way to make software available; users are allowed
         to log in as `guest' without a password and copy whatever
         has been made available [syn: anonymous ftp, anonymous
         file transfer protocol]

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

anonymous FTP

    An interactive service provided by many
   Internet hosts allowing any user to transfer documents,
   files, programs, and other archived data using File Transfer
   Protocol.  The user logs in using the special user name
   "ftp" or "anonymous" and his e-mail address as password.
   He then has access to a special directory hierarchy containing
   the publically accessible files, typically in a subdirectory
   called "pub".  This is usually a separate area from files used
   by local users.

   A reference like

   	ftp: euagate.eua.ericsson.se /pub/eua/erlang/info

   means that files are available by anonymous FTP from the host
   called euagate.eua.ericsson.se in the directory (or file)
   /pub/eua/erlang/info.  Sometimes the hostname will be
   followed by an Internet address in parentheses.  The
   directory will usually be given as a path relative to the
   anonymous FTP login directory.  A reference to a file
   available by FTP may also be in the form of a URL starting
   "ftp:".

   See also Archie, archive site, EFS, FTP by mail,
   web.

   (1995-11-26)