(often capitalized) Of or relating to the New Age movement. / Of or relating to New Age music.

(often capitalized) A modern spiritual and religious movement, covering a wide variety of alternative spiritual and philosophical ideas, that developed towards the end of the 20th century.

(history) A period of time ranging from part of the 17ᵗʰ century through much of the 18ᵗʰ century, characterized particularly by the importance of logic and reason.

A restriction placed on an activity based on the age of the participants; either lower or higher limit.

(idiomatic) A period of happiness, peace, prosperity, and/or great progress. / (mythology) The Golden Age.

the time of the Industrial Revolution

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.