The definition for the “Poop Deck” as found in nautical…

““The definition for the “Poop Deck” as found in nautical books would lead you to believe that the name was derived from the French word for the stern of the ship, la poupe which in turn was derived from the Latin puppis. On sailing ships this deck was higher than the main deck, making it ideal to navigate from. It also was where the binnacle and ship’s wheel were located for the helmsman. The deck of the poop deck formed the roof or overhead of the Captain’s cabin making it convenient for the Captain to reach. His after cabin was frequently irreverently referred to as the “poop cabin!” As wooden ships with iron men were replace with wooden men on iron ships, the navigational functions, with the exception of setting the sails, were moved to the bridge. According to my father who was a ship’s cook in the early 1920’s, the term poop deck remained, but took on a totally different meaning. During the turn of the last century, with coal fired reciprocating steam engines replacing wind and sails, this rear deck was where animals were kept to be butchered for food. Salted meat packed in barrels and the lack of fresh vegetables was the frequent cause of constipation and even worse scurvy. Many ships of that era, and before, didn’t yet have refrigeration and this was the way they continued to have fresh meat. A cabin boy tended to the chickens, pigs, lambs and goats and it was up to the butcher or cooks to slaughter and quarter them. Of course the deck nearest the stern was ideal for this, leaving the ensuing smell behind in the wake of the ship. Seldom is the term “Poop Deck” used now since with the advent of cruise ships nautical terms are fading. Bunks have become beds, cabins became staterooms and the head is now the restroom. Oh, what has become of the days of yore?””

— Captain Hank Bracker, "Seawater One