age (n.)

late 13c., "long but indefinite period in human history," from Old French aage, eage (12c., Modern French âge) "age; life, lifetime, lifespan; maturity," earlier edage (11c.), from Vulgar Latin *aetaticum (source also of Spanish edad, Italian eta, Portuguese idade "age"), extended form of Latin aetatem (nominative aetas), "period of life, age, lifetime, years," from aevum "lifetime, eternity, age," from PIE root *aiw- "vital force, life; long life, eternity"

Expelled native eld (Old English eald) "old age; an age; age as a period of life." Meaning "time something has lived, particular length or stage of life" is from early 14c. Used especially for "old age" since early 14c.; meaning "effects of old age" (feebleness, senility, etc.) is from mid-15c. In geology, in reference to great periods in the history of the earth, 1855; in archaeology, from 1865 (Stone Age, etc.) naming periods for the materials employed for weapons and tools. Sometimes in early modern English "a century" (similar to French siècle "century," literally "an age"), hence plural use in Dark Ages, Middle Ages. To act (one's) age "behave with appropriate maturity" is attested by 1927.

age (v.)

late 14c., "grow old," from age (n.). Transitive meaning "make old" is early 15c.

Definitions of age
age (n.)
how long something has existed;
it was replaced because of its age
age (n.)
an era of history having some distinctive feature;
we live in a litigious age
Synonyms: historic period
age (n.)
a time of life (usually defined in years) at which some particular qualification or power arises;
she was now of school age
Synonyms: eld
age (n.)
a prolonged period of time;
we've known each other for ages
Synonyms: long time / years
age (n.)
a late time of life;
old age is not for sissies
age hasn't slowed him down at all
Synonyms: old age / years / eld / geezerhood
age (v.)
begin to seem older; get older;
The death of his wife caused him to age fast
age (v.)
grow old or older;
She aged gracefully
we age every day--what a depressing thought!
Synonyms: senesce / get on / mature / maturate
age (v.)
make older;
The death of his child aged him tremendously