muck around vs monkey

muck around is not a noun while monkey is a noun.

Word	Noun	Adjective	Verb	Adverb
muck around	No	No	Yes	No
monkey	Yes	No	Yes	No

As verbs, muck around and monkey are synonyms defined as:

muck around and monkey: do random, unplanned work or activities or spend time idly

Other synonyms of muck around include mess around, monkey around, muck about, potter, putter, tinker.

muck around (noun)	monkey (noun)
	any of various long-tailed primates (excluding the prosimians)
	one who is playfully mischievous

muck around (verb)	monkey (verb)
do random, unplanned work or activities or spend time idly	do random, unplanned work or activities or spend time idly
	play around with or alter or falsify, usually secretively or dishonestly