(Australia) Younger than the oldest age permitted to participate in a competition, and therefore eligible to participate in its next season.

Early adolescence.

The period of United States history from the end of the Civil War to the end of the 19th century, a time marked by rapid economic expansion, a lack of government regulation, and rampant corruption.

(UK) The age after retirement but while one is still young enough to be active; young old age.

Of or related to day-age creationism.

The current era, characterised by the widespread and increasing use of digital technology in society.

(anthropology) An established social category or group consisting of people born during a certain time span who together move through a series of culturally defined age grades.

(anthropology) An organized, culturally defined social category of people with membership based on age; in some societies it is entered automatically when one reaches a certain age, while in others it is entered through an initiation rite and/or the payment of a fee.

(US, slang, dated) A very long time.

(mythology) One of the five ages of man, the period at which semidivine and human heroes are purported to have lived, between the arrival of the Greeks to Thessaly and the Greek return from Troy.