putter vs muck around

putter is a noun but muck around is not a noun.

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

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

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

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

putter (noun)	muck around (noun)
the iron normally used on the putting green
a golfer who is putting

putter (verb)	muck around (verb)
move around aimlessly	do random, unplanned work or activities or spend time idly
do random, unplanned work or activities or spend time idly
work lightly