Source : Webster's Revised Unabridged Dictionary (1913)

Aloft \A*loft"\ (?; 115), adv. [Pref. a- + loft, which properly
   meant air. See {Loft}.]
   1. On high; in the air; high above the ground. ``He steers
      his flight aloft.'' --Milton.

   2. (Naut.) In the top; at the mast head, or on the higher
      yards or rigging; overhead; hence (Fig. and Colloq.), in
      or to heaven.

Aloft \A*loft"\, prep.
   Above; on top of. [Obs.]

         Fresh waters run aloft the sea.          --Holland.

Source : WordNet®

aloft
     adv 1: at or on or to the masthead or upper rigging of a ship;
            "climbed aloft to unfurl the sail"
     2: upward; "the good news sent her spirits aloft"
     3: at or to great height; high up in or into the air; "eagles
        were soaring aloft"; "dust is whirled aloft"
     4: in the higher atmosphere above the earth; "weather
        conditions aloft are fine"