The Free On-line Dictionary of Computing (19 January 2023):

CTY

   /sit'ee/ or /C-T-Y/ [MIT] The terminal physically associated
   with a computer's system console.  The term is a contraction
   of "Console tty", that is, "Console TeleTYpe".  This ITS-
   and TOPS-10-associated term has become less common, as most
   Unix hackers simply refer to the CTY as "the console".

   [Jargon File]