Wordnet 3.0
NOUN (1)
1. 
 a post marking the starting point of a race (especially a horse race); 
The Collaborative International Dictionary of English v.0.48:
Starting \Start"ing\ (st[aum]rt"[i^]ng),
   a. & n. from Start, v.
   [1913 Webster]
   Starting bar (Steam Eng.), a hand lever for working the
      valves in starting an engine.
   Starting hole, a loophole; evasion. [Obs.]
   Starting point, the point from which motion begins, or from
      which anything starts.
   Starting post, a post, stake, barrier, or place from which
      competitors in a race start, or begin the race.
      [1913 Webster]
WordNet (r) 3.0 (2006):
starting post
    n 1: a post marking the starting point of a race (especially a
         horse race)