Proposal retained common ground (14)
I believe the answer is:
recommendation
'proposal' is the definition.
(I know that recommendation is a type of advice)
'retained common ground' is the wordplay.
'ground' indicates an anagram ('grind' the letters into a new form).
'retained'+'common'='retainedcommon'
'retainedcommon' anagrammed gives 'RECOMMENDATION'.
(Other definitions for recommendation that I've seen before include "Suggestion as to the best course of action" , "testimonial" , "good word!" .)