Ringing man after proposal (8)
I believe the answer is:
plangent
'ringing' is the definition.
(synonyms)
'man after proposal' is the wordplay.
'man' becomes 'gent' (gent is a kind of man).
'after' says to put letters next to each other.
'proposal' becomes 'plan' (a proposal is a plan of action).
'gent' put after 'plan' is 'PLANGENT'.
(Other definitions for plangent that I've seen before include "Resounding" , "Clangorous" , "(Of sound) mournfully resonant" , "loud noise" , "Loud and sad" .)