Quaternary (adjective)
definition:
coming next after the third and just before the fifth in position or time or degree or magnitude
example:
"the quaternary period of geologic time extends from the end of the tertiary period to the present"
Synonyms
FourthQuaternary (adjective)
definition:
consisting of or especially arranged in sets of four
Synonyms
QuaternateQuaternary (noun)
definition:
the cardinal number that is the sum of three and one
Synonyms
Four