- (a.) Being of the third formation, order or rank; third; as, a tertiary use of a word.
- (a.) Growing on the innermost joint of a bird's wing; tertial; -- said of quills.
- (a.) Later than or subsequent to, the Secondary.
- (n.) 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.
- (n.) One of the quill feathers which are borne upon the basal joint of the wing of a bird. See Illust. of Bird.
- (a.) 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.
- (n.) The Tertiary era, period or formation.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). Tertiary. Retrieved September 23, 2026, from http://smartdefine.org/tertiary/definitions/2071430 |
| Chicago | Webster's. 2011. "Tertiary" http://smartdefine.org/tertiary/definitions/2071430 (accessed September 23, 2026). |
| Harvard | Webster's 2011, Tertiary, Smart Define, viewed 23 September, 2026, <http://smartdefine.org/tertiary/definitions/2071430>. |
| MLA | Webster's. "Tertiary" 28 May 2011. Web. 23 September 2026. <http://smartdefine.org/tertiary/definitions/2071430> |