Looking for thermionic emission? Find out information about thermionic emission. emission of electrons electron, elementary particle carrying a unit charge of negative electricity. Ordinary electric current is the flow of electrons... Explanation of thermionic emission
M stands for medium width. It depends if the 10M was on a pair of mens shoes or womens shoes. A 10M in Mens shoes would be a 11 in womens shoes.
The M in military designations stands for Model. What the AR in AR15 stands for has been the subject of more than one discussion on this site. Originally, I believe, it was supposed to stand for Armalite; the company that developed the piece. When Colt bought the rights to build the gun, AR sort of started to mean Automatic Rifle; so take your pick[:D]