NOUN (2)

1. (Greek mythology) the immortal winged horse that sprang from the blood of the slain Medusa; was tamed by Bellerophon with the help of a bridle given him by Athena; as the flying horse of the Muses it is a symbol of highflying imagination;

2. a constellation in the northern hemisphere near Andromeda and Pisces;

The Collaborative International Dictionary of English v.0.48:

Pegasus \Peg"a*sus\, n. [L., fr. Gr. Ph`gasos.]
   1. (Gr. Myth.) A winged horse fabled to have sprung from the
      body of Medusa when she was slain. He is noted for
      causing, with a blow of his hoof, Hippocrene, the
      inspiring fountain of the Muses, to spring from Mount
      Helicon. On this account he is, in modern times,
      associated with the Muses, and with ideas of poetic
      inspiration.
      [1913 Webster]

            Each spurs his jaded Pegasus apace.   --Byron.
      [1913 Webster]

   2. (Astron.) A northen constellation near the vernal
      equinoctial point. Its three brightest stars, with the
      brightest star of Andromeda, form the square of Pegasus.
      [1913 Webster]

   3. (Zool.) A genus of small fishes, having large pectoral
      fins, and the body covered with hard, bony plates. Several
      species are known from the East Indies and China.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Pegasus
    n 1: (Greek mythology) the immortal winged horse that sprang
         from the blood of the slain Medusa; was tamed by
         Bellerophon with the help of a bridle given him by Athena;
         as the flying horse of the Muses it is a symbol of
         highflying imagination
    2: a constellation in the northern hemisphere near Andromeda and
       Pisces

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

Pegasus

   1.  A product to support Internet
   searches, electronic mail, and Usenet news.

   [Details?  Addesss?]

   (1997-07-14)

   2.  An open source project run by The Open Group
   which implements a Common Information Model (CIM) Object
   Manager.

   Pegasus Home (http://openpegasus.org/).

   (2003-06-07)