Firework sailor finds excellent (11)
I believe the answer is:
crackerjack
'excellent' is the definition.
(thesaurus)
'firework sailor' is the wordplay.
'firework' becomes 'cracker' (cracker is a kind of firework).
'sailor' becomes 'jack' (I've seen this before).
'cracker'+'jack'='CRACKERJACK'
'finds' acts as a link.
(Other definitions for crackerjack that I've seen before include "Excellent (person or thing)" , "Exceptional (thing or person) - 1970s' children's programme" , "Exceptionally good" , "Wonderful (person or thing)" .)