The Collaborative International Dictionary of English v.0.48:

System \Sys"tem\, n. [L. systema, Gr. ?, fr. ? to place
   together; sy`n with + ? to place: cf. F. syst[`e]me. See
   Stand.]
   1. An assemblage of objects arranged in regular
      subordination, or after some distinct method, usually
      logical or scientific; a complete whole of objects related
      by some common law, principle, or end; a complete
      exhibition of essential principles or facts, arranged in a
      rational dependence or connection; a regular union of
      principles or parts forming one entire thing; as, a system
      of philosophy; a system of government; a system of
      divinity; a system of botany or chemistry; a military
      system; the solar system.
      [1913 Webster]

            The best way to learn any science, is to begin with
            a regular system, or a short and plain scheme of
            that science well drawn up into a narrow compass.
                                                  --I. Watts.
      [1913 Webster]

   2. Hence, the whole scheme of created things regarded as
      forming one complete plan of whole; the universe. "The
      great system of the world." --Boyle.
      [1913 Webster]

   3. Regular method or order; formal arrangement; plan; as, to
      have a system in one's business.
      [1913 Webster]

   4. (Mus.) The collection of staves which form a full score.
      See Score, n.
      [1913 Webster]

   5. (Biol.) An assemblage of parts or organs, either in animal
      or plant, essential to the performance of some particular
      function or functions which as a rule are of greater
      complexity than those manifested by a single organ; as,
      the capillary system, the muscular system, the digestive
      system, etc.; hence, the whole body as a functional unity.
      [1913 Webster]

   6. (Zool.) One of the stellate or irregular clusters of
      intimately united zooids which are imbedded in, or
      scattered over, the surface of the common tissue of many
      compound ascidians.
      [1913 Webster]

   Block system, Conservative system, etc. See under
      Block, Conservative, etc.
      [1913 Webster] Systematic

WordNet (r) 3.0 (2006):

system
    n 1: instrumentality that combines interrelated interacting
         artifacts designed to work as a coherent entity; "he bought
         a new stereo system"; "the system consists of a motor and a
         small computer"
    2: a group of independent but interrelated elements comprising a
       unified whole; "a vast system of production and distribution
       and consumption keep the country going" [syn: system,
       scheme]
    3: (physical chemistry) a sample of matter in which substances
       in different phases are in equilibrium; "in a static system
       oil cannot be replaced by water on a surface"; "a system
       generating hydrogen peroxide"
    4: a complex of methods or rules governing behavior; "they have
       to operate under a system they oppose"; "that language has a
       complex system for indicating gender" [syn: system, system
       of rules]
    5: an organized structure for arranging or classifying; "he
       changed the arrangement of the topics"; "the facts were
       familiar but it was in the organization of them that he was
       original"; "he tried to understand their system of
       classification" [syn: arrangement, organization,
       organisation, system]
    6: a group of physiologically or anatomically related organs or
       parts; "the body has a system of organs for digestion"
    7: a procedure or process for obtaining an objective; "they had
       to devise a system that did not depend on cooperation"
    8: the living body considered as made up of interdependent
       components forming a unified whole; "exercise helped him get
       the alcohol out of his system"
    9: an ordered manner; orderliness by virtue of being methodical
       and well organized; "his compulsive organization was not an
       endearing quality"; "we can't do it unless we establish some
       system around here" [syn: organization, organisation,
       system]

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

system

   1. The supervisor program or operating system on a
   computer.

   2. The entire computer system, including input/output devices,
   the supervisor program or operating system and possibly
   other software.

   3. Any large program.

   4. Any method or algorithm.

   [Jargon File]


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

system
 n.

    1. The supervisor program or OS on a computer.

    2. The entire computer system, including input/output devices, the
    supervisor program or OS, and possibly other software.

    3. Any large-scale program.

    4. Any method or algorithm.

    5. System hacker: one who hacks the system (in senses 1 and 2 only; for
    sense 3 one mentions the particular program: e.g., LISP hacker)