noun, feminine/medjaˈluna/plural: medialunas
crescent (shape); medialuna (crescent-shaped corral used in rodeo); medialuna (crescent-shaped pastry); penalty arc, semicircle, the D (an arc whose center is the penalty spot, extending from the top of the penalty area)
Synonyms: semicírculo
Univerbation of media + luna, literally “half moon”.