Head of stinking fish for captain (7)
I believe the answer is:
skipper
'captain' is the definition.
(synonyms)
'head of stinking fish' is the wordplay.
'head of' indicates taking the first letters.
'fish' becomes 'kipper' (type of fish).
The first letter of 'stinking' is 's'.
's'+'kipper'='SKIPPER'
'for' is the link.
(Other definitions for skipper that I've seen before include "being in charge?" , "who makes short hops" , "sleep in outhouse" , "Captain of team or boat - type of butterfly" , "Chap aboard trawler" .)