The realm of intellectual property which is not or no longer protected by copyrights or patents, and thus over which no person can establish a proprietary interest.
The state of not or no longer being confidential or secret.
Land regarded as owned by the public, and not subject to a land patent or other forms of private ownership (for example, unowned prairie in the southwestern and western United States).
The state of not being owned by anyone, and thus freely usable by everyone.
Not under copyright.