I. ˈkwä-tə(r)-ˌner-ē, kwə-ˈtər-nə-rē adjective
Etymology: Latin quaternarius, from quaterni four each
Date: 1605
1.
a. : of, relating to, or consisting of four units or members
b. : of, relating to, or being a number system with a base of four
2. capitalized : of, relating to, or being the geological period from the end of the Tertiary to the present time or the corresponding system of rocks — see geologic time table
3. : consisting of, containing, or being an atom bonded to four other atoms
II. noun
( plural -ries )
Date: 1880
1. capitalized : the Quaternary period or system of rocks
2. : a member of a group fourth in order or rank