Found 2 items, similar to Tertiary period.
English → English (WordNet) Definition: Tertiary period Tertiary period n : from 63 million to 2 million years ago [syn: Tertiary]
English → English (gcide) Definition: Tertiary period Tertiary \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. [1913 Webster] 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. [1913 Webster] 3. (Geol.) Later than, or subsequent to, the Secondary. [1913 Webster] 4. (Zo["o]l.) Growing on the innermost joint of a bird's wing; tertial; -- said of quills. [1913 Webster] 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. [1913 Webster]