Pronunciation: (ar"u-stär'kus),[key] —n. 1. of Samos. late 3rd century b.c., Greek astronomer.
2. of Samothrace. c216–144 b.c., Greek philologist and critic.
3. an extremely bright crater in the second quadrant of the face of the moon: about 29 miles (47 km) in diameter from crest to crest.