 it was named thus because its first parts are black and the rest of it is white with the moon. it is said that a sheep is draa if its head is black and the rest of it is white and a third is dadi and a third is dhalam because of its darkness.
سميت بذلك لأسوداد اوائلها، وابيضاض سائرها بالقمر. ويقال شاة درعاء، إذا اسود رأسها وابيض سائرها وثلث دآدئ وثلث ظلم لاظلامها.