What is the meaning of Untie?

To loosen, as something interlaced or knotted; to disengage the parts of.

To free from fastening or from restraint; to let loose; to unbind.

To resolve; to unfold; to clear.

To become untied or loosed.

In the Perl programming language, to undo the process of tying, so that a variable uses default instead of custom functionality.

Source: wiktionary.org