standstill vs tie-up

standstill and tie-up both are nouns.

Word	Noun	Adjective	Verb	Adverb
standstill	Yes	No	No	No
tie-up	Yes	No	No	No

As nouns, standstill and tie-up are synonyms defined as:

Other synonyms of standstill include stand.

standstill (noun)	tie-up (noun)
an interruption of normal activity	an interruption of normal activity
a situation in which no progress can be made or no advancement is possible	a social or business relationship