The Early Semitic pictograph for this letter is a picture of waves of water. This pictograph has the meanings of liquid, water and sea, mighty and massive from the size of the sea and chaos from the storms of the sea. To the Hebrews the sea was a feared and unknown place, for this reason this letter is used as a question word, who, what, when, where, why and how, in the sense of searching for an unknown.
The modern Hebrew name for this letter is “mem” probably from the word “mayim” meaning “water”. The word “mayim” is the plural form of “mah”, probably the original name for this letter, meaning “what”. The Greek name for this letter is “mu”, a Hebrew word closely related to “mah”. The sound for this letter is “m”.
The Early Semitic evolved into in the Middle Semitic and continued to evolve into in the Late Semitic script. The Late Semitic script became the מ and ם (final mem) of the Modern Hebrew script. The Early and Middle Semitic script is the origin to the Greek and Roman M.