Source : Webster's Revised Unabridged Dictionary (1913)

Commencement \Com*mence"ment\, n. [F. commencement.]
   1. The first existence of anything; act or fact of
      commencing; rise; origin; beginning; start.

            The time of Henry VII. . . . nearly coincides with
            the commencement of what is termed ``modern
            history.''                            --Hallam.

   2. The day when degrees are conferred by colleges and
      universities upon students and others.

Source : WordNet®

commencement
     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}, {first}, {outset}, {get-go},
           {start}, {kickoff}, {starting time}, {showtime}, {offset}]
          [ant: {middle}, {end}]
     2: an academic exercise in which diplomas are conferred [syn: {commencement
        exercise}, {commencement ceremony}, {graduation}, {graduation
        exercise}]
     3: the act of starting something; "he was responsible for the
        beginning of negotiations" [syn: {beginning}, {start}]
        [ant: {finish}]