Any mechanism or operation that unwinds something.

(transitive) To separate (something that is wound up)

(transitive, obsolete) To disentangle

(intransitive, colloquial) To relax; to chill out; to rest and become relieved of stress

(intransitive) To be or become unwound; to be capable of being unwound or untwisted.

(transitive, finance) To close out a position, especially a complicated position.

(transitive, finance) To undo something.

(transitive, programming) To analyse (a call stack) so as to generate a stack trace etc.