The Collaborative International Dictionary of English v.0.48:

Outset \Out"set`\, n.
   A setting out, starting, or beginning. "The outset of a
   political journey." --Burke.
   [1913 Webster]

         Giving a proper direction to this outset of life. --J.
                                                  Hawes.
   [1913 Webster]

WordNet (r) 3.0 (2006):

outset
    n 1: the time at which something is supposed to begin; "they got
         an early start"; "she knew from the get-go that he was the
         man for her" [syn: beginning, commencement, first,
         outset, get-go, start, kickoff, starting time,
         showtime, offset] [ant: end, ending, middle]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "outset":
   A, alpha, beginning, birth, blast-off, commencement, creation,
   cutting edge, dawn, dawning, edge, establishment, first,
   flying start, foundation, fresh start, inauguration, inception,
   institution, jump-off, kick-off, leading edge, new departure,
   oncoming, onset, opening, origin, origination, outbreak,
   outsetting, outstart, running start, send-off, setoff, setout,
   setting in motion, setting-up, square one, start, start-off,
   starting, starting point, take-off, takeoff