Half-cut, perhaps, I knocked over container for fish (7)
I believe the answer is:
halibut
'fish' is the definition.
(I know that halibut is a type of fish)
'half-cut perhaps i knocked over container' is the wordplay.
'cut perhaps' means to remove the last letter.
'knocked over' says the letters should be written backwards.
'container' becomes 'tub' (tub is a kind of container).
'tub' in reverse letter order is 'but'.
'half' with its last letter removed is 'hal'.
'hal'+'i'+'but'='HALIBUT'
'for' is the link.
(Other definitions for halibut that I've seen before include "Utah lib (anag)" , "Large flatfish used as food" , "Swimmer" , "Largest flatfish" , "Fish found in Bali hut" .)