Propose a toast in part for The Bench (4)
I believe the answer is:
seat
'the bench' is the definition.
(I've seen this in another clue)
'propose a toast in part' is the wordplay.
'in part' indicates a hidden word.
'SEAT' can be found hidden inside 'propose a toast'.
'for' is the link.
(Other definitions for seat that I've seen before include "'A chair, say (4)'" , "Spanish car" , "Chair, bench, saddle, etc" , "Parliamentary constituency" , "Sitting place" .)