(idiomatic) In the current era of history.

The age at which a child is presumed to be able to judge the difference between right and wrong / (theology) The time of the Last Judgment

(US, colloquial) A long time; many years.

(Roman Catholicism) Seven years of age, at which age a person is morally liable for the sins that he or she commits.

(archaeology) A short or theoretical prehistoric period between the Neolithic and Bronze Age.

plural of coming of age

(medicine) The apparent age of a child based on the maturity of its bones.

(horse racing) Handicapped according to the age of the racehorse competing (and certain other factors).

(horse racing) A weight for age race.

The age of an individual, measured in days, months and years from the time the individual was born, often used in psychometrics.