4th 4th /fɔrθ/

adjective

1. () Coming next after the third and just before the fifth in position, time, degree or magnitude  ( quaternary , 4th , fourth )
   coming next after the third and just before the fifth in position, time, degree or magnitude
    The quaternary period of geologic time extends from the end of the tertiary period to the present
   the quaternary period of geologic time extends from the end of the tertiary period to the present