From WordNet (r) 2.0 (August 2003) [wn]:
Emperor
n 1: the male ruler of an empire [syn: Emperor]
2: red table grape of California
3: large moth of temperate forests of Eurasia having heavily
scaled transparent wings [syn: emperor moth, {Saturnia
pavonia}]
4: large richly colored butterfly [syn: emperor butterfly]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Emperor \Em"per*or\, n. [OF. empereor, empereour, F. empereur,
L. imperator, fr. imperare to command; in in + parare to
prepare, order. See Parade, and cf. Imperative,
Empress.]
The sovereign or supreme monarch of an empire; -- a title of
dignity superior to that of king; as, the emperor of Germany
or of Austria; the emperor or Czar of Russia.
[1913 Webster]
Emperor goose (Zo["o]l.), a large and handsome goose
(Philacte canagica), found in Alaska.
Emperor moth (Zo["o]l.), one of several large and beautiful
bombycid moths, with transparent spots on the wings; as
the American Cecropia moth (Platysamia cecropia), and
the European species (Saturnia pavonia).
Emperor paper. See under Paper.
Purple emperor (Zo["o]l.), a large, strong British
butterfly (Apatura iris).
[1913 Webster]