The Collaborative International Dictionary of English v.0.48:

Perfection \Per*fec"tion\, n. [F. perfection, L. perfectio.]
   1. The quality or state of being perfect or complete, so that
      nothing requisite is wanting; entire development;
      consummate culture, skill, or moral excellence; the
      highest attainable state or degree of excellence;
      maturity; as, perfection in an art, in a science, or in a
      system; perfection in form or degree; fruits in
      perfection.
      [1913 Webster]

   2. A quality, endowment, or acquirement completely excellent;
      an ideal faultlessness; especially, the divine attribute
      of complete excellence. --Shak.
      [1913 Webster]

            What tongue can her perfections tell? --Sir P.
                                                  Sidney.
      [1913 Webster]

   To perfection, in the highest degree of excellence;
      perfectly; as, to imitate a model to perfection.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Perfection \Per*fec"tion\, v. t.
   To perfect. [Obs.] --Foote.
   [1913 Webster]

WordNet (r) 3.0 (2006):

perfection
    n 1: the state of being without a flaw or defect [syn:
         perfection, flawlessness, ne plus ultra] [ant:
         imperfection, imperfectness]
    2: an ideal instance; a perfect embodiment of a concept [syn:
       paragon, idol, perfection, beau ideal]
    3: the act of making something perfect

The Devil's Dictionary (1881-1906):

PERFECTION, n.  An imaginary state of quality distinguished from the
actual by an element known as excellence; an attribute of the critic.
    The editor of an English magazine having received a letter
pointing out the erroneous nature of his views and style, and signed
"Perfection," promptly wrote at the foot of the letter:  "I don't
agree with you," and mailed it to Matthew Arnold.