The Collaborative International Dictionary of English v.0.48:

Majority \Ma*jor"i*ty\, n.; pl. Majorities. [F. majorit['e].
   See Major.]
   1. The quality or condition of being major or greater;
      superiority. Specifically:
      (a) The military rank of a major.
      (b) The condition of being of full age, or authorized by
          law to manage one's own affairs.
          [1913 Webster]

   2. The greater number; more than half; as, a majority of
      mankind; a majority of the votes cast.
      [1913 Webster]

   3. [Cf. L. majores.] Ancestors; ancestry. [Obs.]
      [1913 Webster]

   4. The amount or number by which one aggregate exceeds all
      other aggregates with which it is contrasted; especially,
      the number by which the votes for a successful candidate
      exceed those for all other candidates; as, he is elected
      by a majority of five hundred votes. See Plurality.
      [1913 Webster]

   To go over to the majority or To join the majority, to
      die.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

73 Moby Thesaurus words for "majority":
   accomplishment, adulthood, adultness, age of consent, ascendancy,
   best part, better part, body, bulk, deanship, driving age, essence,
   excellence, favor, flower of age, full age, full bloom,
   full growth, fullgrownness, generality, gist, gravamen, greatness,
   grown-upness, incomparability, inimitability, lead, legal age,
   legalis homo, main body, major part, manhood, manlihood, mass,
   mature age, maturity, meat, more than half, most, one-upmanship,
   plurality, precedence, predominance, predomination, preeminence,
   preponderance, preponderancy, prepotence, prepotency, prerogative,
   prestige, prime, prime of life, priority, privilege, right-of-way,
   ripe age, riper years, seniority, skill, substance, success,
   superiority, the greatest number, thrust, toga virilis,
   transcendence, transcendency, virility, virtuosity, womanhood,
   womanlihood, years of discretion