Peter Giles

“ The Phoenician name of the symbol was mem, the Greek name μῦ is formed on the analogy of the name for n. M represents the bilabial nasal sound, which was generally voiced. It is commonly a stable sound, but many languages, e.g. Greek, Germanic and Celtic, change it when final into -n, its dental correlative. It appears more frequently as an initial sound in Greek and Latin than in the other languages of the same stock, because in these s before m (as also before l and n) disappeared at the beginning of words. ”