tertiary

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Third in place, order, degree, or rank.
• adjective Of, relating to, or designating the short flight feathers nearest the body on the rear edge of a bird's wing.
• adjective Of, relating to, or having a carbon atom that is attached to three other carbon atoms in a molecule.
• adjective Of or relating to the replacement of three of several atoms or groups in a compound, such as an amine in which three valences of the functional group are taken by carbon atoms.
• adjective Of or relating to salts of acids containing three replaceable hydrogen atoms.
• adjective Of, relating to, or being the period of geologic time from about 65 to about 1.8 million years ago, the older of the two periods of the Cenozoic Era. The Tertiary Period is characterized by the appearance of modern flora, insects, fish, amphibians, and reptiles, and by the dominance of mammals as vertebrate life forms on land.
• noun A tertiary feather.
• noun The Tertiary Period.
• noun Roman Catholic Church A member of a religious Third Order.

from The Century Dictionary.

• Of the third order, rank, or formation; third.
• In geology, of, pertaining to, or occurring in the Tertiary. See II. .
• In ornithology, same as tertial: distinguished from secondary and from primary. See cuts under bird and covert, n., 6.
• Belonging or pertaining To the Tertiaries. See II. .
• noun One who or that which is tertiary, or third in order or succession.
• noun A color, as russet, citrine, or olive, produced by the mixture of two secondary colors. Tertiaries are grays, and are either red-gray, blue-gray, or yellow-gray when these primaries are in excess, or violet-gray, orange-gray, or green-gray when these secondaries are in excess.
• noun Same as tertial.

from the GNU version of the Collaborative International Dictionary of English.

• noun (R. C. Ch.) A member of the Third Order in any monastic system. See Third Order, under third.
• noun (Geol.) The Tertiary era, period, or formation.
• noun (Zoöl.) One of the quill feathers which are borne upon the basal joint of the wing of a bird. See Illust. of Bird.
• adjective Being of the third formation, order, or rank; third.
• adjective (Chem.) Possessing some quality in the third degree; having been subjected to the substitution of three atoms or radicals. Cf. Primary, and Secondary.
• adjective (Geol.) Later than, or subsequent to, the Secondary.
• adjective (Zoöl.) Growing on the innermost joint of a bird's wing; tertial; -- said of quills.
• adjective (Geol.) See under Age, 8.
• adjective a color produced by the mixture of two secondaries.
• adjective (Geol.) The rock formation of that period; -- called also Tertiary formation. See the Chart of Geology.
• adjective (Med.) the third and last stage of syphilis, in which it invades the bones and internal organs.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Of third rank or order; subsequent.
• noun A tertiary feather.
• noun A member of a Roman Catholic third order - the Franciscans, Dominicans and Carmelites among others.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun from 63 million to 2 million years ago
• adjective coming next after the second and just before the fourth in position