The Collaborative International Dictionary of English v.0.48:
Mikado \Mi*ka"do\, n. [Jap.] The popular designation of the hereditary sovereign of Japan; the emperor of Japan. [1913 Webster]WordNet (r) 3.0 (2006):
mikado n 1: the emperor of Japan; when regarded as a religious leader the emperor is called tenno [syn: mikado, tenno]