Leo

Concise Oxford English Dictionary © 2008 Oxford University Press:
Leo/ˈliːəʊ/

▶noun

• 1 Astronomy a large constellation (the Lion), said to represent the lion slain by Hercules.

• 2 Astrology the fifth sign of the zodiac, which the sun enters about 23 July.

– derivatives
Leonian noun & adjective.

– origin from L.