/terr"neuh ree/ , adj., n., pl. ternaries .
adj.
1. consisting of or involving three; threefold; triple.
2. third in order or rank.
3. based on the number three.
4. Chem.
a. consisting of three different elements or groups.
b. (formerly) consisting of three atoms.
5. Math. having three variables.
6. Metall. (of an alloy) having three principal constituents.
n.
7. a group of three.
[ 1400-50; late ME ternarius made up of three. See TERN 2 , -ARY ]