He'd epic plan to reform furniture designer (11)
I believe the answer is:
chippendale
'furniture designer' is the definition.
(I know that Chippendale has the occupation furniture designer)
'he'd epic plan to reform' is the wordplay.
'to reform' indicates anagramming the letters (letters in a new form).
'hed'+'epic'+'plan'='hedepicplan'
'hedepicplan' anagrammed gives 'CHIPPENDALE'.
(Other definitions for chippendale that I've seen before include "18th century furniture designer" , "stripper" , "18th-century style of chairs and cabinets" , "Type of furniture" , "Furniture maker" .)