Pronunciation: (u-pol'ō),[key] —n., —pl.-losfor 2, 3. 1. the ancient Greek and Roman god of light, healing, music, poetry, prophecy, and manly beauty; the son of Leto and brother of Artemis.
2. a very handsome young man.
3. Aerospace.one of a series of U.S. spacecraft designed to carry astronauts to the moon and back.