The Collaborative International Dictionary of English v.0.48:

Vigesimo-quarto \Vi*ges"i*mo-quar"to\, n.; pl. -tos.
   A book composed of sheets each of which is folded into
   twenty-four leaves; hence, indicating more or less definitely
   a size of book so made; -- usually written 24mo, or 24[deg].
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Anito \A*ni"to\, n.; pl. -tos. [Sp.]
   In Guam and the Philippines, an idol, fetich, or spirit.
   [Webster 1913 Suppl.]

V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

TOS
       The Operating System (Atari, OS)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

TOS
       Tramiel Operating System (Atari, OS)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

TOS
       Type Of Service (IP)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

TOS
       Tape Operating System (OS, RCA Spectra 70)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

TOS
       Teletype Operating System (OS, Microdata)


The Jargon File (version 4.4.7, 29 Dec 2003):

TOS
 vt.

    [from the acronym for ?Terms Of Service? playing on the verb ?toss?]

    1. The act of terminating an Internet access account because the owner
    breached the terms of service (e.g. by spamming).

    2. To successfully complain to the ISP for that reason so that they then
    close the account.


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

TOS

    /toss/

   1. IBM's Tape Operating System.

   2. The operating system of the Atari ST range of
   computers.  This range included the 512ST, 1040ST and the F,
   FM and E variations (e.g.1040STE).  Later, 32-bit machines
   (TT, Falcon030 and MegaSTE) were developed using a new version
   of TOS, called MultiTOS which was based on MinT.

   TOS went through several revisions starting initially as a
   derivative of CP/M, but developing into a remarkably
   complete and flexible operating system.  Features include: a
   flat memory model, MS-DOS-compatible disk format and
   support for MIDI and SCSI (in later versions).  TOS was
   designed to run Atari's version of the GEM GUI.

   There is some argument as to what TOS stands for, the main
   candidates being "Tramiel Operating System" (named after
   Atari's head at the time) or simply "The Operating System".

   3.  Terms Of Service.

   4. Star Trek The Original Series as opposed to ST-TNG or
   ST-DS9.

   (1999-04-02)