public domain

Short definition from Wiktionary

Noun

1. 1
   Often preceded by in the: The state of not being owned by anyone, and thus freely usable by everyone.
2. 2
   The state of not being owned by anyone, and thus freely usable by everyone: 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.
3. 3
   Often preceded by in the: The state of not or no longer being confidential or secret.
4. 4
   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).