WordNet (r) 3.0 (2006):

forward motion
    n 1: the act of moving forward (as toward a goal) [syn:
         progress, progression, procession, advance,
         advancement, forward motion, onward motion] [ant:
         retreat]

Moby Thesaurus II by Grady Ward, 1.0:

67 Moby Thesaurus words for "forward motion":
   Brownian movement, advance, advancement, advancing, angular motion,
   ascending, ascent, axial motion, backflowing, backing,
   backward motion, career, climbing, course, current, descending,
   descent, downward motion, drift, driftage, ebbing, flight, flow,
   flux, forwardal, forwarding, furtherance, furthering, go-ahead,
   headway, march, mounting, oblique motion, ongoing, onrush,
   onward course, passage, plunging, progress, progression,
   progressiveness, promotion, radial motion, random motion,
   reflowing, refluence, reflux, regression, retrogression, rising,
   rolling, rolling on, run, rush, set, sideward motion, sinking,
   soaring, sternway, stream, subsiding, traject, trajet, travel,
   trend, upward motion, way