tertiary age

1 definition found

tertiary age - Collaborative International Dictionary of English v.0.48 :

  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.
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     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.
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     3. (Geol.) Later than, or subsequent to, the Secondary.
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     4. (Zool.) Growing on the innermost joint of a bird's wing;
        tertial; -- said of quills.
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     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.
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