What sounds like rough plan of action (6)
I believe the answer is:
course
'plan of action' is the definition.
(thesaurus)
'what sounds like rough' is the wordplay.
'what sounds like' shows a homophone (sound like).
'rough' becomes 'coarse' ('coarse' is associated in meaning with 'rough').
'coarse' is a homophone of 'COURSE'.
(Other definitions for course that I've seen before include "fish, possibly" , "Venue for race or golf tournament" , "Each separate part of meal" , "Source (anag.)" , "Path of a river or a set of lessons" .)