King's throne? (4)
I believe the answer is:
john
I believe this clue is a double definition.
'king's' is the first definition.
(I know that John is a King of England)
'throne?' is the second definition.
(both can informally mean a toilet)
(Other definitions for john that I've seen before include "Matthew, Mark, Luke and . . . ." , "With nineteen accross twentieth century US actor known for westerns, etc" , "a dear letter" , "Old King" , "English king in play" .)