Real Dictionary

throne
countable noun: A throne is a decorative chair used by a king, queen, or emperor on important official occasions.
singular noun: You can talk about the throne as a way of referring to the position of being king, queen, or emperor.

throne in American English
the chair on which a king, cardinal, etc. sits on formal or ceremonial occasions: it usually is on a dais, covered with a canopy, and highly decorated
to sit on or as on a throne
noun: the chair or seat occupied by a sovereign, bishop, or other exalted personage on ceremonial occasions, usually raised on a dais and covered with a canopy

throne in British English
noun: the ceremonial seat occupied by a monarch, bishop, etc on occasions of state
verb: to place or be placed on a throne