M
magnanimity of mind
majesty of despair
man of iron
mantle of verdure [verdure = lush greenness of flourishing vegetation]
martyrdom of ambition
marvel of competency
mask of flippancy
mass of mediocrity
master of phrasing
maze of words
measure of absurdity
minister of vengeance
minuteness of description
miracle of miracles
mists of criticism
modesty of reserve
moment of lassitude
monster of ingratitude
monstrosities of character
mood of tranquillity
muddle of motives
multitude of details
mummery of words [mummery = meaningless ceremonies and flattery]
murmur of satisfaction
mutations of time
myriads of stars
mysteries of taste