tie up vs fasten

tie up and fasten both are verbs.

Word	Noun	Adjective	Verb	Adverb
tie up	No	No	Yes	No
fasten	No	No	Yes	No

As verbs, fasten is a hypernym of tie up; that is, fasten is a word with a broader meaning than tie up:

Other hypernyms of tie up include fix, secure.

tie up (verb)	fasten (verb)
secure with or as if with ropes	make tight or tighter
finish the last row	become fixed or fastened
restrain from moving or operating normally	cause to be firmly attached
secure in or as if in a berth or dock	attach to
invest so as to make unavailable for other purposes