Definition:
quaternary
- quaternaryOf, relating to, or denoting the most recent period in the Cenozoic era, following the Tertiary period and comprising the Pleistocene and Holocene epochs (and thus including the present)
- quaternaryDenoting an ammonium compound containing a cation of the form NR4+, where R represents organic groups or atoms other than hydrogen
- quaternary(of a carbon atom) Bonded to four other carbon atoms
- quaternaryFourth in order or rank; belonging to the fourth order
- quaternarya set of four