Queequeg's captain (4)
I believe the answer is:
ahab
'queequeg's captain' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ahab that I've seen before include "Spring bulbs" , "Melville's whale chaser" , "Husband of Jezebel" , "Captain of the whaler Pequod" , "Name of captain seeking Moby Dick" .)