muck around vs monkey around

muck around and monkey around both are verbs.

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

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

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

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

muck around (verb)	monkey around (verb)
do random, unplanned work or activities or spend time idly	do random, unplanned work or activities or spend time idly