House in Surrey or Kent (4)
I believe the answer is:
york
'house' is the definition.
(I know that York is a type of royal family)
'in surrey or kent' is the wordplay.
'in' indicates the answer is hidden within the clue.
'YORK' is hidden within 'surrey or kent'.
(Other definitions for york that I've seen before include "Northern English cathedral city" , "10 [HOUSE]" , "English royal house" , "Eboracum (L)" , "'Made glorious summer by this sun of - - ' Shakespeare's Richard III" .)