Source : Webster's Revised Unabridged Dictionary (1913)

Tiptoe \Tip"toe`\, n.; pl. {Tiptoes}.
   The end, or tip, of the toe.

         He must . . . stand on his typtoon [tiptoes].
                                                  --Chaucer.

         Upon his tiptoes stalketh stately by.    --Spenser.

   {To be}, or {To stand}, {a tiptoe} or {on tiptoe}, to be
      awake or alive to anything; to be roused; to be eager or
      alert; as, to be a tiptoe with expectation.