undo vs untangle

undo and untangle both are verbs.

Word	Noun	Adjective	Verb	Adverb
undo	No	No	Yes	No
untangle	No	No	Yes	No

As verbs, untangle is a hyponym of undo; that is, untangle is a word with a more specific, narrower meaning than undo:

undo: cancel, annul, or reverse an action or its effect
untangle: become or cause to become undone by separating the fibers or threads of

undo (verb)	untangle (verb)
cancel, annul, or reverse an action or its effect	become or cause to become undone by separating the fibers or threads of
cause to become loose	release from entanglement of difficulty
remove the outer cover or wrapping of
deprive of certain characteristics
cause the ruin or downfall of