Source : Webster's Revised Unabridged Dictionary (1913)

Streamline \Stream"line`\, a.
   Of or pert. to a stream line; designating a motion or flow
   that is free from turbulence, like that of a particle in a
   streamline; hence, designating a surface, body, etc., that is
   designed so as to afford an unbroken flow of a fluid about
   it, esp. when the resistance to flow is the least possible;
   as, a streamline body for an automobile or airship.

Source : WordNet®

streamline
     v : contour economically or efficiently