Main Entry: ¹qua·ter·na·ry

Pronunciation: \ˈkwä-tə(r)-ˌner-ē, kwə-ˈtər-nə-rē\

Function: 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