untied vs unfastened

untied and unfastened both are adjectives.

Word	Noun	Adjective	Verb	Adverb
untied	No	Yes	No	No
unfastened	No	Yes	No	No

As adjectives, untied and unfastened are synonyms defined as:

untied (adjective)	unfastened (adjective)
not tied	not closed or secured
with laces not tied	not buttoned
not bound by shackles and chains	not tied
	affording unobstructed entrance and exit; not shut or closed