(historical) A historical period of great accomplishment in a field or a society, usually following, and not quite as favorable as, a golden age, and not unfavorable as an iron age.

Belonging in the Stone Age.

(idiomatic) To reach a specific age where one is legally considered to be an adult. / (idiomatic) To mature, or become fully developed.

The age in which nuclear energy and nuclear weapons were developed.

The era, starting in the mid-1940s, during which nuclear energy was developed, and in which it was thought that all energy would be provided by such sources.

The chronological age of individuals of the same maturity as the person in question.

The period from the about the time of the launch of Sputnik in 1957 to the present day, during which people ventured into space. / (attributive) Redolent of the space age; appearing futuristic or modern.

Alternative letter-case form of space age

(idiomatic) A time period of years or more.

Synonym of prehistory: the era before written records.