The Collaborative International Dictionary of English v.0.48:

Age \Age\ ([=a]j), n. [OF. aage, eage, F. [^a]ge, fr. L. aetas
   through a supposed LL. aetaticum. L. aetas is contracted fr.
   aevitas, fr. aevum lifetime, age; akin to E. aye ever. Cf.
   Each.]
   1. The whole duration of a being, whether animal, vegetable,
      or other kind; lifetime.
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            Mine age is as nothing before thee.   --Ps. xxxix.
                                                  5.
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   2. That part of the duration of a being or a thing which is
      between its beginning and any given time; as, what is the
      present age of a man, or of the earth?
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   3. The latter part of life; an advanced period of life;
      seniority; state of being old.
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            Nor wrong mine age with this indignity. --Shak.
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   4. One of the stages of life; as, the age of infancy, of
      youth, etc. --Shak.
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   5. Mature age; especially, the time of life at which one
      attains full personal rights and capacities; as, to come
      of age; he (or she) is of age. --Abbott.

   Note: In the United States, both males and females are of age
         when twenty-one years old. Some rights, such as that of
         voting in elections, are conferred earlier.
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   6. The time of life at which some particular power or
      capacity is understood to become vested; as, the age of
      consent; the age of discretion. --Abbott.
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   7. A particular period of time in history, as distinguished
      from others; as, the golden age, the age of Pericles. "The
      spirit of the age." --Prescott.
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            Truth, in some age or other, will find her witness.
                                                  --Milton.
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   Note: Archeological ages are designated as three: The Stone
         age (the early and the later stone age, called
         paleolithic and neolithic), the Bronze age, and the
         Iron age. During the Age of Stone man is supposed to
         have employed stone for weapons and implements.
         [1913 Webster] See Augustan, Brazen, Golden,
         Heroic, Middle.
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   8. A great period in the history of the Earth.
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   Note: The geologic ages are as follows: 1. The Arch[ae]an,
         including the time when was no life and the time of the
         earliest and simplest forms of life. 2. The age of
         Invertebrates, or the Silurian, when the life on the
         globe consisted distinctively of invertebrates. 3. The
         age of Fishes, or the Devonian, when fishes were the
         dominant race. 4. The age of Coal Plants, or Acrogens,
         or the Carboniferous age. 5. The Mesozoic or Secondary
         age, or age of Reptiles, when reptiles prevailed in
         great numbers and of vast size. 6. The Tertiary age, or
         age of Mammals, when the mammalia, or quadrupeds,
         abounded, and were the dominant race. 7. The Quaternary
         age, or age of Man, or the modern era. --Dana.
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   9. A century; the period of one hundred years.
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            Fleury . . . apologizes for these five ages.
                                                  --Hallam.
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   10. The people who live at a particular period; hence, a
       generation. "Ages yet unborn." --Pope.
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             The way which the age follows.       --J. H.
                                                  Newman.
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             Lo! where the stage, the poor, degraded stage,
             Holds its warped mirror to a gaping age. --C.
                                                  Sprague.
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   11. A long time. [Colloq.] "He made minutes an age."
       --Tennyson.
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   12. (poker) the right belonging to the player to the left of
       the dealer to pass the first round in betting, and then
       to come in last or stay out; also, the player holding
       this position; the eldest hand.
       [Webster 1913 Suppl.]

   Age of a tide, the time from the origin of a tide in the
      South Pacific Ocean to its arrival at a given place.

   Moon's age, the time that has elapsed since the last
      preceding conjunction of the sun and moon.
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   Note: Age is used to form the first part of many compounds;
         as, agelasting, age-adorning, age-worn, age-enfeebled,
         agelong.
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   Syn: Time; period; generation; date; era; epoch.
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