The Collaborative International Dictionary of English v.0.48:

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; -- the
   current usuage prefers the term streamlined.
   [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

streamline \stream"line\, v. t.
   1. to design or modify so as to present the least possible
      resistance to fluid flow; -- used mostly of vehicles, such
      as automobiles, airplanes, or ships.
      [PJC]

   2. [Fig.] to change so as to make more efficient; -- used
      especially of organizations, procedures, or methods. "The
      streamlined company became a formidable competitor."
      [PJC]

WordNet (r) 3.0 (2006):

streamline
    v 1: contour economically or efficiently

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "streamline":
   air line, axis, beeline, boil down, chord, diagonal, diameter,
   direct line, directrix, distill, edge, great-circle course,
   modernize, narrow, normal, oversimplify, perpendicular, purify,
   radius, radius vector, reduce, reduce to elements, refine,
   right line, secant, segment, shortcut, side, simplify, straight,
   straight course, straight line, straight stretch, straightaway,
   strip down, tangent, transversal, update, vector