M.M. vs metronome marking

M.M. and metronome marking both are nouns.

Word	Noun	Adjective	Verb	Adverb
M.M.	Yes	No	No	No
metronome marking	Yes	No	No	No

As nouns, M.M. and metronome marking are synonyms defined as:

M.M. and metronome marking: the pace of music measured by the number of beats occurring in 60 seconds

Other synonyms of M.M. include beats per minute, bpm.

M.M. (noun)	metronome marking (noun)
the pace of music measured by the number of beats occurring in 60 seconds	the pace of music measured by the number of beats occurring in 60 seconds