The Collaborative International Dictionary of English v.0.48:

Graduation \Grad"u*a"tion\, n. [LL. graduatio promotion to a
   degree: cf. F. graduation division into degrees.]
   [1913 Webster]
   1. The act of graduating, or the state of being graduated;
      as, graduation of a scale; graduation at a college;
      graduation in color; graduation by evaporation; the
      graduation of a bird's tail, etc.
      [1913 Webster]

   2. The marks on an instrument or vessel to indicate degrees
      or quantity; a scale.
      [1913 Webster]

   3. The exposure of a liquid in large surfaces to the air, so
      as to hasten its evaporation.
      [1913 Webster]

WordNet (r) 3.0 (2006):

graduation
    n 1: the successful completion of a program of study
    2: an academic exercise in which diplomas are conferred [syn:
       commencement, commencement exercise, commencement
       ceremony, graduation, graduation exercise]
    3: a line (as on a vessel or ruler) that marks a measurement;
       "the ruler had 16 graduations per inch"
    4: the act of arranging in grades [syn: gradation,
       graduation]