The Collaborative International Dictionary of English v.0.48:

Utility \U*til"i*ty\, n. [OE. utilite, F. utilit['e], L.
   utilitas, fr. utilis useful. See Utile.]
   [1913 Webster]
   1. The quality or state of being useful; usefulness;
      production of good; profitableness to some valuable end;
      as, the utility of manure upon land; the utility of the
      sciences; the utility of medicines.
      [1913 Webster]

            The utility of the enterprises was, however, so
            great and obvious that all opposition proved
            useless.                              --Macaulay.
      [1913 Webster]

   2. (Polit. Econ.) Adaptation to satisfy the desires or wants;
      intrinsic value. See Note under Value, 2.
      [1913 Webster]

            Value in use is utility, and nothing else, and in
            political economy should be called by that name and
            no other.                             --F. A.
                                                  Walker.
      [1913 Webster]

   3. Happiness; the greatest good, or happiness, of the
      greatest number, -- the foundation of utilitarianism. --J.
      S. Mill.
      [1913 Webster]

   Syn: Usefulness; advantageous; benefit; profit; avail;
        service.

   Usage: Utility, Usefulness. Usefulness has an Anglo-Saxon
          prefix, utility is Latin; and hence the former is used
          chiefly of things in the concrete, while the latter is
          employed more in a general and abstract sense. Thus,
          we speak of the utility of an invention, and the
          usefulness of the thing invented; of the utility of an
          institution, and the usefulness of an individual. So
          beauty and utility (not usefulness) are brought into
          comparison. Still, the words are often used
          interchangeably.
          [1913 Webster]

WordNet (r) 3.0 (2006):

utility
    adj 1: used of beef; usable but inferior [syn: utility(a),
           utility-grade]
    2: capable of substituting in any of several positions on a
       team; "a utility infielder" [syn: utility(a),
       substitute(a)]
    n 1: a company that performs a public service; subject to
         government regulation [syn: utility, public utility,
         public utility company, public-service corporation]
    2: the quality of being of practical use [syn: utility,
       usefulness] [ant: inutility, unusefulness,
       uselessness]
    3: the service (electric power or water or transportation)
       provided by a public utility; "the cost of utilities never
       decreases"; "all the utilities were lost after the hurricane"
    4: (economics) a measure that is to be maximized in any
       situation involving choice
    5: (computer science) a program designed for general support of
       the processes of a computer; "a computer system provides
       utility programs to perform the tasks needed by most users"
       [syn: utility program, utility, service program]
    6: a facility composed of one or more pieces of equipment
       connected to or part of a structure and designed to provide a
       service such as heat or electricity or water or sewage
       disposal; "the price of the house included all utilities"

Moby Thesaurus II by Grady Ward, 1.0:

102 Moby Thesaurus words for "utility":
   Aktiengesellschaft, account, advantage, advantageousness,
   aktiebolag, alternate, alternative, appliance, applicability,
   appropriateness, availability, backup, beneficialness,
   body corporate, business, business establishment, cartel,
   chamber of commerce, combine, commercial enterprise, compagnie,
   company, concern, conglomerate, conglomerate corporation,
   consolidating company, consortium, convenience, copartnership,
   corporate body, corporation, counterfeit, diversified corporation,
   drive, dummy, effectiveness, efficacy, efficiency, engine,
   enginery, enterprise, equivalent, ersatz, facility, fake,
   favorableness, firm, fitness, fixture, functionality, helpfulness,
   holding company, house, imitation, industry,
   joint-stock association, joint-stock company, machine, machinery,
   makeshift, mechanical aid, mechanical device, mechanism, mock,
   motive power, motor, operability, operating company, partnership,
   phony, pinch, plunderbund, pool, power plant, power source,
   practicability, practical utility, practicality, profitability,
   provisional, proxy, public utility, relevance, reserve, secondary,
   service, serviceability, spare, stock company, stopgap, substitute,
   syndicate, temporary, tentative, token, trade association, trust,
   usability, use, usefulness, utilizability, vicarious



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

utility software
utility
utility program

    (Or utility program, tool) Any software that performs
   some specific task that is secondary to the main purpose of
   using the computer (the latter would be called application
   programs) but is not essential to the operation of the
   computer (system software).

   Many utilities could be considered as part of the system
   software, which can in turn be considered part of the
   operating system.

   The following are some broad categories of utility software,
   specific types and examples.

   * Disks

   disk formatter: FDISK, format

   defragmenter

   disk checker: fsck

   disk cleaner

   system profiler

   backup

   file system compression

   * Files and directories

   list directory: ls, dir

   copy, move, remove: cp, mv, rm, xcopy

   archive: tar

   compression: zip

   format conversion: atob

   comparison: diff

   sort: sort

   * Security

   authentication: login

   antivirus software: avast, Norton Antivirus

   firewall: Zone Alarm, Windows firewall

   encryption: gpg)

   * Editors for general-purpose formats (as opposed to specific
   formats like a word processing document)

   text editor: Emacs

   binary editor, hex editor

   * Communications

   mail transfer agent: sendmail

   e-mail notification: biff

   file transfer: ftp, rcp, Firefox

   file synchronisation: unison, briefcase

   chat: Gaim, cu

   directory services: bind, nslookup, whois

   network diagnosis: ping, traceroute

   remote access: rlogin, ssh

   * Software development

   compiler: gcc

   build: make, ant

   codewalker

   preprocessor: cpp

   debugger: adb, gdb

   installation: apt-get, msiexec, patch

   compiler compiler: yacc

   * Hardware

   device configuration: PCU, devman, stty

   (2007-02-02)