moon
n.— «Then I straightened out the front wheels, somehow managing to keep the Zamboni from coming to an ice-melting dead stop.…Nodding shamefully, I quit my showboating and refocused my attention on driving. I made 10 more passes around the rink without serious incident. I did miss a few spots, leaving slivers of nonresurfaced ice called moons.» —“Here, a Nick While Shaving Could Determine the Stanley Cup” by Harry Hurt III New York Times Oct. 6, 2007. (source: Double-Tongued Dictionary)