Outside the realm of a person's experience; specifically out in the world; in existence.
Reality or the world as external to and independent of any person perceiving it; objective reality.
Designating or relating to the perceived rather than the perceiver; specifically having an objective existence, external to, and independent of any perceiver.
2 informal Weird, offbeat, ‘way out’; not mainstream, avant-garde.
Late 18th century; earliest use found in Charles Dibdin (bap. 1745, d. 1814), actor, composer, and writer. From out + there.