MN is the written short form of Minnesota, a state in the north of the United States, up by Canada, known for lakes and cold winters. You write it in addresses, on envelopes, in tables, and on maps. It is the two-letter post-office form the US uses for every state. Out loud you say “Minnesota”; you almost never say the letters M-N unless you are reading a list. It is a label on the page, not a word you have a conversation with.