high muckamuck vs high-up

high muckamuck and high-up both are nouns.

Word	Noun	Adjective	Verb	Adverb
high muckamuck	Yes	No	No	No
high-up	Yes	No	No	No

As nouns, high muckamuck and high-up are synonyms defined as:

high muckamuck and high-up: an important or influential (and often overbearing) person

Other synonyms of high muckamuck include dignitary, panjandrum, very important person, VIP.

high muckamuck (noun)	high-up (noun)
an important or influential (and often overbearing) person	an important or influential (and often overbearing) person