Plan, invent (6)
I believe the answer is:
devise
I believe this clue is a double definition.
'plan' is the first definition.
(synonyms)
'invent' is the second definition.
(I know that invent can be written as devise)
(Other definitions for devise that I've seen before include "Create, work out" , "Make (a plan)" , "Come up with, a plan perhaps" , "Plan invent" , "Formulate or invent" .)