Untie
Part of speech: verb
Definition: To loosen, as something interlaced or knotted; to disengage the parts of; as, to untie a knot. To free from fastening or from restraint; to let loose; to unbind. To resolve; to unfold; to clear. To become untied or loosed.
Loosen
Part of speech: verb
Definition: make something less tight; unfasten
Example sentence: When I'm writing a new play, there's a period where I know I shouldn't be out in public much. I imagine most people who create go through something like this. You willfully loosen some of the inner straps that hold your core together.