(law) The age at which the rights and privileges of an adult are legally granted or recognized; i.e.; the age where a person ceases to be a minor legally and becomes a legal adult.

The latter part of life, the part of life after one's prime.

(sciences) A period of long-term reduction in the temperature of Earth's surface and atmosphere, resulting in the presence of major polar ice sheets that reach the ocean and calve icebergs.

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

(archaeology, paleontology) A broad prehistoric period during which humans widely used stone for toolmaking. / (figuratively, informal) Any extremely primitive or undeveloped era.

(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.

very old; having existed for a long time; ancient or well-established

(mythology) The most recent and debased of the four or five classical Ages of Man; hence, any period characterized by wicked behavior. / An age characterized by the use of iron.

Of or relating to a broad movement in Western culture, covering a wide variety of alternative spiritual and philosophical ideas, often spirituality, mysticism, holism, and environmentalism, and partially based on eastern religions such as Buddhism and Hinduism, that developed towards the end of the 20th century.