"Chunk light" fish (4)
I believe the answer is:
tuna
'chunk light fish' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tuna that I've seen before include "Large fish for the strange aunt" , "Type of fish" , "Widely-eaten fish" , "Fish sold in cans" , "Popular food fish" .)