Marvelous
Or Modelesque (urban dictionary) Meaning having the look of a model.
Modernize is a word that starts with m and means to upgrade.
Make is a word that means to create and starts with "m".
The word you are looking for is "clever."
The word is magnificent.
mountainous
monarch
Misery
"Matter" is a possibility.
Muscle.
Merge
mimic
Mane?