President's laundry not returned (10)
I believe the answer is:
washington
'president's' is the definition.
(George Washington, first president of the USA)
'laundry not returned' is the wordplay.
'laundry' becomes 'washing' (I've seen this before).
'returned' says the letters should be written in reverse.
'not' in reverse letter order is 'ton'.
'washing'+'ton'='WASHINGTON'
(Other definitions for washington that I've seen before include "NW US state" , "Seattle's state" , "American general and president" , "See 3" , "State - capital - president" .)