Rubbish former Queen and King Edward? (5)
I believe the answer is:
tater
'king edward?' is the definition.
(King Edward is a type of potato)
'rubbish former queen' is the wordplay.
'rubbish' becomes 'tat' (low-quality items or material).
'former queen' becomes 'ER' (Elizabeth Regina, ie Queen Elizabeth).
'tat'+'er'='TATER'
'and' acts as a link.
(Other definitions for tater that I've seen before include "Potato (colloq.)" , "Potato (informal)" , "Champ is mostly" , "found in vegetable basket" , "Spud" .)