When one gets upset at something or someone than decides not to take "the man upstairs" name in vain therefore blurting out "Dag nammit". Also used by midwest rednecks.
Dag nammit Girtrude you done did it again and broke my dang ol' rifle, now how I'm going to catch me some possum?
by Doogie Howser M.D. February 19, 2009