n.1 the sovereign of an empire.
2 a sovereign of higher rank than a king.
Phrases and idioms:
emperor moth a large moth, Saturnia pavonia, of the silk-moth family, with eye-spots on all four wings. emperor penguin the largest known penguin, Aptenodytes forsteri, of the Antarctic.
Derivatives:
emperorship n.
Etymology: ME f. OF emperere, empereor f. L imperator -oris f. imperare command