Source : Webster's Revised Unabridged Dictionary (1913)

Step \Step\, v. t.
   1. To set, as the foot.

   2. (Naut.) To fix the foot of (a mast) in its step; to erect.

   {To step off}, to measure by steps, or paces; hence, to
      divide, as a space, or to form a series of marks, by
      successive measurements, as with dividers.