Pompous fool one found on ship (3)
I believe the answer is:
ass
'pompous fool' is the definition.
(I've seen this before)
'one found on ship' is the wordplay.
'one' becomes 'a'.
'found on' is a charade indicator (letters next to each other).
'ship' becomes 'ss'.
'a'+'ss'='ASS'
(Other definitions for ass that I've seen before include "jack" , "Braying creature" , "Titania loved one" , "Stupid person or American bum" , "Long-eared animal" .)