Assuming that you mean two ms together ("mm"), the answer is yes, there are many words with two ms.
Command, immune, immoral, dilemma, lemming, commit, clamming, hammer, immature, immolate, hummed, and scamming are just a very few of them. The list is far too numerous to try to elaborate beyond that.
Two animal behavior words starting with M are mating and migration.
M&M Meats or Magellan Minerals?
minimum
ammoniaammunitionbrimmingbummerchummeddimmerdrummerflammablegrimmergrommetglimmergrammarhammerhummerimmerseimmurejammedmammalpummelrimmedshimmersummerslammerskimmerslimmersimmerswimmerswimmingtrimmer
yes
amum
Magic Markers
maybe
Woman & Man
"Any day" is always two words. "Anyday" is incorrect.
no not really, mf is two words and is mf if not going to say the actual words
Miami Beach is a place with two words that start with M and B. Manhattan Beach and Malibu Beach are others.