The Collaborative International Dictionary of English v.0.48:

omega \o*me"ga\ ([=o]*m[=e]"g[.a] or [=o]*m[=a]"g[.a] or
   [=o]"m[-e]*g[.a]; 277), n. [NL., fr. Gr. 'w^ me`ga, i.e., the
   great or long o. Cf. Mickle.]
   1. The last letter of the Greek alphabet. See Alpha.
      [1913 Webster]

   2. The last; the end; hence, death.
      [1913 Webster]

            "Omega! thou art Lord," they said.    --Tennyson.
      [1913 Webster]

   Alpha and Omega, the beginning and the ending; hence, the
      chief, the whole. --Rev. i. 8.
      [1913 Webster]

            The alpha and omega of science.       --Sir J.
                                                  Herschel.
      [1913 Webster]

WordNet (r) 3.0 (2006):

omega
    n 1: the ending of a series or sequence; "the Alpha and the
         Omega, the first and the last, the beginning and the end"--
         Revelation [syn: omega, Z]
    2: the last (24th) letter of the Greek alphabet

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "omega":
   Z, apodosis, catastrophe, ceasing, cessation, coda, conclusion,
   consummation, crack of doom, culmination, curtain, curtains, death,
   decease, denouement, destination, destiny, doom, effect, end,
   end point, ending, envoi, epilogue, eschatology, expiration, fate,
   final solution, final twitch, final words, finale, finality, finis,
   finish, goal, izzard, last, last breath, last gasp, last things,
   last trumpet, last words, latter end, payoff, period, peroration,
   quietus, resolution, resting place, stoppage, stopping place,
   swan song, term, terminal, termination, terminus, windup



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

Omega

   1.  A prototype-based object-oriented
   language from Austria.

   ["Type-Safe Object-Oriented Programming with Prototypes - The
   Concept of Omega", G. Blaschek, Structured Programming
   12:217-225, 1991].

   2.  A successor to TeX extended to handle the
   Unicode character set.

   (http://ens.fr/omega/).

   (1997-11-20)


Easton's 1897 Bible Dictionary:

Omega
   (Rev. 1:8), the last letter in the Greek alphabet. (See A.)


Hitchcock's Bible Names Dictionary (late 1800's):

Omega, the last letter of the Greek alphabet; long O


U.S. Gazetteer Places (2000):

Omega, GA -- U.S. city in Georgia
   Population (2000):    1340
   Housing Units (2000): 522
   Land area (2000):     1.775647 sq. miles (4.598904 sq. km)
   Water area (2000):    0.005642 sq. miles (0.014613 sq. km)
   Total area (2000):    1.781289 sq. miles (4.613517 sq. km)
   FIPS code:            58184
   Located within:       Georgia (GA), FIPS 13
   Location:             31.339684 N, 83.595036 W
   ZIP Codes (1990):     31775
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Omega, GA
    Omega