Definition of "quarterly"

quarterly

adjective
not comparable
1. Occurring once every quarter year (three months).
2. (heraldry) (of a coat of arms) Divided into four parts crosswise.
adverb
not comparable
1. Once every quarter year (three months).
2. (heraldry) In the four, or in two diagonally opposite, quarters of a shield.
  Quotations
  It consisted of the arms of the City of London, Middlesex (three seaxes, or Saxon swords), Buckingham (a swan), and Hertford (a hart), arranged quarterly, on a background of crimson and ermine mantling […] .
  1950 June, Michael Robbins, “Heraldry of London Underground Railways”, in Railway Magazine, page 380
noun
plural quarterlies
1. A periodical publication that appears four times per year.