Office (6)
'office' is the definition.
(I know that office can be written as bureau)
This is all the clue.
(Other definitions for bureau that I've seen before include "Chest of drawers or office" , "Wtiting desk" , "Office; writing desk" , "Writing desk with drawers" , "Ancient chipped flint" .)
(Other definitions for oval that I've seen before include "not quite round" , "sports ground" , "Like eggs" , "Easter gift" , "Squashed circle" .)