Source : Webster's Revised Unabridged Dictionary (1913)

Maxim \Max"im\, n. [F. maxime, L. maxima (sc. sententia), the
   greatest sentence, proposition, or axiom, i. e., of the
   greatest weight or authority, fem. fr. maximus greatest,
   superl. of magnus great. See {Magnitude}, and cf. {Maximum}.]
   1. An established principle or proposition; a condensed
      proposition of important practical truth; an axiom of
      practical wisdom; an adage; a proverb; an aphorism.

            'T is their maxim, Love is love's reward. --Dryden.

   2. (Mus.) The longest note formerly used, equal to two longs,
      or four breves; a large.

   Syn: Axiom; aphorism; apothegm; adage; proverb; saying. See
        {Axiom}.

Source : WordNet®

maxim
     n 1: a saying that widely accepted on its own merits [syn: {axiom}]
     2: English inventor (born in the United States) who invented
        the Maxim gun that was used in World War I (1840-1916)
        [syn: {Sir Hiram Stevens Maxim}]