The Collaborative International Dictionary of English v.0.48:

Adage \Ad"age\, n. [F. adage, fr. L. adagium; ad + the root of
   L. aio I say.]
   An old saying, which has obtained credit by long use; a
   proverb.
   [1913 Webster]

         Letting "I dare not" wait upon "I would,"
         Like the poor cat i' the adage.          --Shak.
   [1913 Webster]

   Syn: Axiom; maxim; aphorism; proverb; saying; saw; apothegm.
        See Axiom.
        [1913 Webster]

WordNet (r) 3.0 (2006):

adage
    n 1: a condensed but memorable saying embodying some important
         fact of experience that is taken as true by many people
         [syn: proverb, adage, saw, byword]

The Devil's Dictionary (1881-1906):

ADAGE, n.  Boned wisdom for weak teeth.