Staggering fish caught by crew (7)
I believe the answer is:
reeling
'staggering' is the definition.
('reel' can be a synonym of 'stagger')
'fish caught by crew' is the wordplay.
'fish' becomes 'eel' (eel is a kind of fish).
'caught by' indicates putting letters inside.
'crew' becomes 'ring' (both can mean a group of people).
'eel' put inside 'ring' is 'REELING'.
(Other definitions for reeling that I've seen before include "Stunned - staggering" , "Unable properly to control one's movements" , "Dancing; staggering" , "may be off-balance" , "Staggering around" .)