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

pseudo-tty

    Berkeley Unix networking device which appears
   to an application program as an ordinary terminal but which is in
   fact connected via the network to a process running on a different
   host or a windowing system.  Pseudo-ttys have a slave half and a
   control half.  The slave tty (/dev/ttyp*) is the device that user
   programs use and the control tty (/dev/ptyp*) is used by daemons
   to talk to the net.

   (1994-11-08)