Source : Webster's Revised Unabridged Dictionary (1913)

Fraternity \Fra*ter"ni*ty\, n.; pl. {Fraternities}. [F.
   fraternit['e], L. fraternitas.]
   1. The state or quality of being fraternal or brotherly;
      brotherhood.

   2. A body of men associated for their common interest,
      business, or pleasure; a company; a brotherhood; a
      society; in the Roman Catholic Chucrch, an association for
      special religious purposes, for relieving the sick and
      destitute, etc.

   3. Men of the same class, profession, occupation, character,
      or tastes.

            With what terms of respect knaves and sots will
            speak of their own fraternity!        --South.

Source : WordNet®

fraternity
     n 1: a social club for male undergraduates [syn: {frat}]
     2: people engaged in a particular occupation; "the medical
        fraternity" [syn: {brotherhood}, {sodality}]