Source : Webster's Revised Unabridged Dictionary (1913)

Quarterly \Quar"ter*ly\, a.
   1. Containing, or consisting of, a fourth part; as, quarterly
      seasons.

   2. Recurring during, or at the end of, each quarter; as,
      quarterly payments of rent; a quarterly meeting.

Quarterly \Quar"ter*ly\, n.; pl. {Quarterlies}.
   A periodical work published once a quarter, or four times in
   a year.

Quarterly \Quar"ter*ly\, adv.
   1. By quarters; once in a quarter of a year; as, the returns
      are made quarterly.

   2. (Her.) In quarters, or quarterings; as, to bear arms
      quarterly; in four or more parts; -- said of a shield thus
      divided by lines drawn through it at right angles.

Source : WordNet®

quarterly
     adj : of or relating to or consisting of a quarter; "quarterly
           report"
     n : a periodical that is published every quarter
     adv 1: in diagonally opposed quarters of an escutcheon; "two coats
            of arms borne quarterly"
     2: in three month intervals; "interest is compounded quarterly"
        [syn: {every quarter}]