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.]

WordNet (r) 3.0 (2006):

streamlined
    adj 1: made efficient by stripping off nonessentials; "short
           streamlined meetings"; "a streamlined hiring process"
    2: designed or arranged to offer the least resistant to fluid
       flow; "a streamlined convertible" [syn: streamlined,
       aerodynamic, flowing, sleek]

Moby Thesaurus II by Grady Ward, 1.0:

72 Moby Thesaurus words for "streamlined":
   a la mode, advanced, aerodynamic, arrowlike, automated,
   avant-garde, compact, contemporary, curved, curvilinear,
   dead straight, direct, efficient, even, far out, fashionable, flat,
   flowing, forward-looking, horizontal, hydrodynamic, in, in a line,
   labor-saving, level, lineal, linear, mod, modern, modernistic,
   modernized, modish, newfashioned, now, present-day, present-time,
   productive, profitable, progressive, rectilineal, rectilinear,
   right, ruler-straight, simplified, smooth, straight, straight-cut,
   straight-front, straight-side, stripped down, time-saving, true,
   twentieth-century, ultra-ultra, ultramodern, unbending, unbent,
   unbowed, unbroken, uncurved, undeflected, undeviating, undistorted,
   uninterrupted, unswerving, unturned, up-to-date, up-to-datish,
   up-to-the-minute, upright, vertical, way out