half moon
From Longman Dictionary of Contemporary Englishhalf moonˌhalf ˈmoon noun [countable] TTSthe shape of the moon when only half of it is showing → full moon, new moon(1)Examples from the Corpushalf moon• The moon, a half moon polished thin at the edges, swam low and gave a little light.• Granny flew high above the roaring treetops, under a half moon.• A half moon shone through the dark, flying clouds on to the wild and empty moor.