The male monarch or ruler of an empire.
Any monarch ruling an empire, irrespective of gender, with "empress" contrasting to mean when consort to emperor
(political theory) Specifically, the ruler of the Holy Roman Empire; the world-monarch.
The fourth trump or major arcana card of the tarot deck.
A large, relatively valuable marble in children's games.
Any fish of the family Lethrinidae.
Any various butterflies of the subfamily Charaxinae.