Please find below a list of M adjectives which might be used to describe a person.
Positive
magic
magical
magnetic
magnificent
mannered
marvelous
masterful
maternal
merciful
merriest
merry
meticulous
motherly
Negative
maladjusted
maladroit
malevolent
malicious
maniacal
manic
maniclike
materialistic
mean
meanest
merciless
messy
mettlesome
mindless
mischievous
morbid
muddleheaded
murderous
Other
machinelike
macho
mad
male
malnourished
manly
married
masculine
maudlin
meditative
meek
meekest
melancholy
mellow
melodramatic
methodical
mighty
mild
milder
militant
miserable
moderate
modern
modernistic
modest
monogamous
moody
moral
moralistic
mortal
mournful
mum
muscular
musical
mustached
mute
mysterious
There are many more lists of adjectives on this website. For more adjectives starting in M, see this post containing a large number of adjectives beginning with the letter M, some of which can be used for describing people.
mystical
Missing