N or M
- The letters placed after the first question in the Church Catechism, "What is your name?" to show that the Christian name or names of the person questioned should be given. "N" stands for the Latin word nomen, meaning name; while the letter "M" is an abbreviation of double "N. N.," the "N" being doubled according to an old custom to indicate the plural, viz., nomina, meaning names. The same thing is to be seen in the letters "LL.D." standing for the degree of "Doctor of Laws," the double "LL" signifying the plural legum, meaning "of laws."
American Church Dictionary and Cyclopedia. — New York, Thomas Whittaker. William James Miller, M.A., B.D.. 1901.