(lē′ō)
A masculine personal name; the appellation of thirteen popes, and six Byzantine emperors. [<L, a lion]
—Leo I,
390?–461, pope 440–461; defended Rome against Attila: called “Leo the Great.”
—Leo III,
675?–741; emperor of Byzantium 717–741: called “The Isaurian.”
—Leo III,
750?–816, pope 795–816; crowned Charlemagne as emperor; canonized.
—Leo X,
1475–1521, pope 1513–21: real name Giovanni de' Medici.
—Leo XIII,
1810–1903, pope 1878–1903: real name Gioacchino Pecci.

(lē′ō)
1. The fifth sign of the zodiac, which the sun enters about July 21.
2. A constellation containing the Sickle and the bright star Regulus. See CONSTELLATION. [<NL <L, a lion]