kreisel
n.— «Instead of rectangular tanks, she and her partner, Debbie Melechinsky, use a piece of 10-inch PVC pipe to round out the corners of the tank. It’s called a “kreisel,” from the German word for carousel.» —“Aquarists discuss safe breeding of seahorses” by Hannah Hickey Monterey Herald (California) Dec. 9, 2004. (source: Double-Tongued Dictionary)