the first month of the year, having 31 days: abbrev. Jan, Ja, or J
Origin of JanuaryMiddle English Janyuere from Classical Latin Januarius (mensis), (the month) of Janus, to whom it was sacred
The first month of the year in the Gregorian calendar. calendar
Origin of JanuaryMiddle English Januarie, Jenever from Old North French Jenever from Latin Iānuārius (mēnsis) (month) of Janus from Iānus Janus ; see ei- in Indo-European roots.
(plural Januarys or Januaries)