WordNet (r) 3.0 (2006):

running start
    n 1: a racing start in which the contestants are already in full
         motion when they pass the starting line [syn: flying
         start, running start]
    2: a quick and auspicious beginning [syn: flying start,
       running start]

Moby Thesaurus II by Grady Ward, 1.0:

62 Moby Thesaurus words for "running start":
   A, advantage, alpha, anticipation, beginning, beginnings,
   blast-off, bulge, coign of vantage, commencement, creation,
   cutting edge, dawn, drop, earliness, early hour, early stage, edge,
   establishment, first crack, first stage, flying start, foresight,
   foundation, fresh start, ground floor, head start, inside track,
   institution, jump, jump-off, kick-off, leading edge, new departure,
   odds, oncoming, onset, opening, origin, origination, outbreak,
   outset, prevenience, prevision, readiness, send-off,
   setting in motion, setting-up, something extra,
   something in reserve, square one, start, start-off, starting point,
   take-off, time to spare, upper hand, vantage, vantage ground,
   vantage point, very beginning, whip hand