The Collaborative International Dictionary
Tertiary \Ter"ti*a*ry\, a. [L. tertiarius containing a third part, fr. tertius third: cf. F. tertiaire. See Tierce.]
Being of the third formation, order, or rank; third; as, a tertiary use of a word.
--Trench.(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.
(Geol.) Later than, or subsequent to, the Secondary.
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(Zo["o]l.) 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.)
The first period of the age of mammals, or of the Cenozoic era.
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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.
Usage examples of "tertiary period".
This was also the start of the so-called Tertiary period, or Age of Mammals, so the end of the dinosaurs is usually called the K/T boundary, 'K' because Germans spell Cretaceous with a K.
The leaves were wholly devoid of verdure, and the flowers, so numerous during the Tertiary period which gave them birth, were without color and without perfume, something like paper discolored by long exposure to the atmosphere.
When they travel a little further, they encounter a Tertiary Period forest and a living herd of mastodons ripping away tree branches and eating them.
The K/T boundary is the time when the geological time period known as the Cretaceous Period ended and the Tertiary Period began.
After the extinctions at the end of the Cretaceous, the new Tertiary period's forest canopy became home to this mammal's descendents, the primates.
We know that North America had a very different shape during the Cretaceous or even the Middle Tertiary period from what it has now, and that the Gulf of Mexico extended up the valley of the Mississippi as far as the Ohio, by the presence of a great coral reef in the Ohio River near Cincinnati.
Finally, VIII and IX, the Oligocene and Miocene Epochs of the Tertiary Period, mark the emergence of man's earliest ancestors.
This place here was a coastline some 1,200,000 years back, during the later Tertiary Period.
From the flora and fauna on the tapes, she would have placed Klairos somewhere in the late Tertiary period on the Terran-based geological time scale: late Miocene or early Pliocene.