Source : Webster's Revised Unabridged Dictionary (1913)

Skylark \Sky"lark`\, n. (Zo["o]l.)
   A lark that mounts and sings as it files, especially the
   common species ({Alauda arvensis}) found in Europe and in
   some parts of Asia, and celebrated for its melodious song; --
   called also {sky laverock}. See under {Lark}.

   Note: The Australian skylark ({Cincloramphus cantillans}) is
         a pipit which has the habit of ascending
         perpendicularly like a skylark, but it lacks the song
         of a true lark. The Missouri skylark is a pipit
         ({Anthus Spraguei}) of the Western United States,
         resembling the skylark in habit and song.

Source : WordNet®

skylark
     n : brown-speckled European lark noted for singing while
         hovering at a great height [syn: {Alauda arvensis}]
     v : play boisterously; "The children frolicked in the garden";
         "the gamboling lambs in the meadows"; "The toddlers
         romped in the playroom" [syn: {frolic}, {lark}, {rollick},
          {disport}, {sport}, {cavort}, {gambol}, {frisk}, {romp},
          {run around}, {lark about}]