Civil War reenactors have their own slang (like "farb"), but this list is unique to our reenacting unit.
Canteen Murphy: Noun. A person who refills the canteens for everyone else.
Garryowen: Proper noun. Used instead of "goodbye."
GILBERT!: Exclamation. Always spoken at full volume. It is a direction aimed at one of Paul's sons, as an admonition to stop whatever he is doing. "GILBERT!"
Gilbert Brigade: Proper noun. A reference to the Irish Brigade during the early 2000's, when the 69th Co. B was mostly made up of people with the last name of Gilbert.
lolBilly: Noun. A humorous picture of Billy Coye, with a caption in the style of a lolcat. See icanhascheezburger.com/.
Kill it, skin it, you cook it, tastes nutty: Colloquial phrase. Represents something only a Gilbert would eat. ;-)
MJ: Proper noun. Mother Judy. "Is MJ cooking breakfast?"
New York load: Noun. A double load of black powder. For .58 cal, this is 140 grains. For .69 cal, this is 180 grains. Note: New York load is a violation of the PACWAR safety rules.
Oscar Mike: Gerund. On the move. Uses the modern radio alphabet to represent the abbreviation, O.M., even though the radio alphabet wasn't developed until long after the Civil War. "Come on, we're Oscar Mike!"
Personal reveille: Noun. Describes the bugle call of reveille, performed while the bell of the bugle is inserted between the flaps of someone's tent. Usually performed for those who fail to rise after the first reveille.
Run up a hill: Colloquial phrase. Refers to Sgt. Koplowicz asking everyone to do something physically demanding and totally unnecessary.
Did I miss something? Let me know and I'll add it!