Ter"ti*a*ry (?), a. [L. tertiarius containing a third part, fr. tertius third: cf. F. tertiaire. See Tierce.] 1. Being of the third formation, order, or rank; third; as, a tertiary use of a word.
Trench.
2. Chem. Possessing some quality in the third degree; having been subjected to the substitution of three atoms or radicals; as, a tertiary alcohol, amine, or salt. Cf. Primary, and Secondary.
(CH3)3C.OH. -->
3. Geol. Later than, or subsequent to, the Secondary.
4. Zool. Growing on the innermost joint of a bird's wing; tertial; -- said of quills.
Tertiary age. Geol. See under Age, 8. -- Tertiary color, a color produced by the mixture of two secondaries. "The so-called tertiary colors are citrine, russet, and olive." Fairholt. -- Tertiary period. Geol. (a) The first period of the age of mammals, or of the Cenozoic era. (b) The rock formation of that period; -- called also Tertiary formation. See the Chart of Geology. -- Tertiary syphilis Med., the third and last stage of syphilis, in which it invades the bones and internal organs.
© Webster 1913.
Ter"ti*a*ry, n.; pl. Tertiaries (). 1. R. C. Ch. A member of the Third Order in any monastic system; as, the Franciscan tertiaries; the Dominican tertiaries; the Carmelite tertiaries. See Third Order, under Third.
Addis & Arnold.
2. Geol. The Tertiary era, period, or formation.
3. Zool. One of the quill feathers which are borne upon the basal joint of the wing of a bird. See Illust. of Bird.
© Webster 1913. | 
