For prominent one on board, tribute entertaining political leader (7)
I believe the answer is:
topmast
'for prominent one on board' is the definition.
(type of mast on board a ship)
'tribute entertaining political leader' is the wordplay.
'tribute' becomes 'toast' (I've seen this before).
'entertaining' indicates putting letters inside.
'political leader' becomes 'pm' (abbreviation for prime minister).
'toast' going around 'pm' is 'TOPMAST'.
(Other definitions for topmast that I've seen before include "Sail up here" , "high post" , "Sail-supporting section of a ship" , "High part of sailing ship" , "Part of square-rigged ship" .)