unlink

verb

1. (transitive)To decouple; to remove a link from, or separate the links of.
2. (Unix, transitive)To delete (a file).

   “That's because the permission to unlink a file doesn't depend upon the permission bits on the file itself; it's the permission bits on the directory that contains the file that matter.”

noun

1. A link that is equivalent (under ambient isotopy) to finitely many disjoint circles in the plane.