The Collaborative International Dictionary of English v.0.48:

Sail \Sail\, v. i. [imp. & p. p. Sailed; p. pr. & vb. n.
   Sailing.] [AS. segelian, seglian. See Sail, n.]
   1. To be impelled or driven forward by the action of wind
      upon sails, as a ship on water; to be impelled on a body
      of water by the action of steam or other power.
      [1913 Webster]

   2. To move through or on the water; to swim, as a fish or a
      water fowl.
      [1913 Webster]

   3. To be conveyed in a vessel on water; to pass by water; as,
      they sailed from London to Canton.
      [1913 Webster]

   4. To set sail; to begin a voyage.
      [1913 Webster]

   5. To move smoothly through the air; to glide through the air
      without apparent exertion, as a bird.
      [1913 Webster]

            As is a winged messenger of heaven, . . .
            When he bestrides the lazy pacing clouds,
            And sails upon the bosom of the air.  --Shak.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Sailing \Sail"ing\, n.
   1. The act of one who, or that which, sails; the motion of a
      vessel on water, impelled by wind or steam; the act of
      starting on a voyage.
      [1913 Webster]

   2. (Naut.) The art of managing a vessel; seamanship;
      navigation; as, globular sailing; oblique sailing.
      [1913 Webster]

   Note: For the several methods of sailing, see under
         Circular, Globular, Oblique, Parallel, etc.
         [1913 Webster]

   Sailing master (U. S. Navy), formerly, a warrant officer,
      ranking next below a lieutenant, whose duties were to
      navigate the vessel; and under the direction of the
      executive officer, to attend to the stowage of the hold,
      to the cables, rigging, etc. The grade was merged in that
      of master in 1862.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sailing
    n 1: the work of a sailor [syn: seafaring, navigation,
         sailing]
    2: riding in a sailboat
    3: the departure of a vessel from a port
    4: the activity of flying a glider [syn: glide, gliding,
       sailplaning, soaring, sailing]

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "sailing":
   aeronautics, air service, airline, astronautics, aviation,
   ballooning, blind flying, boating, canoeing, circumnavigation,
   cloud-seeding, coasting, commercial aviation, contact flying,
   cruising, flight, flow, flowing, flying, general aviation, glide,
   gliding, gunkholing, motorboating, navigability, navigating,
   navigation, passage-making, periplus, pilotage, rowing,
   sailplaning, sculling, sea travel, seafaring, skating, skiing,
   skim, sledding, slide, sliding, slipping, slither, slithering,
   soaring, steaming, sweep, sweeping, tobogganing, travel by water,
   voyaging, water travel, winging, yachting