The Collaborative International Dictionary of English v.0.48:

Notary \No"ta*ry\, n.; pl. Notaries. [F. notaire, L. notarius
   notary (in sense 1), fr. nota mark. See 5th Note.]
   [1913 Webster]
   1. One who records in shorthand what is said or done; as, the
      notary of an ecclesiastical body.
      [1913 Webster]

   2. (Eng. & Am. Law) A public officer who attests or certifies
      deeds and other writings, or copies of them, usually under
      his official seal, to make them authentic, especially in
      foreign countries. His duties chiefly relate to
      instruments used in commercial transactions, such as
      protests of negotiable paper, ship's papers in cases of
      loss, damage, etc. He is generally called a notary
      public.
      [1913 Webster]

WordNet (r) 3.0 (2006):

notary public
    n 1: someone legally empowered to witness signatures and certify
         a document's validity and to take depositions [syn:
         notary, notary public]