Careful about tinned food? (5)
I believe the answer is:
canny
'careful' is the definition.
(I've seen this in another clue)
'about tinned food?' is the wordplay.
'about' becomes 'c' (abbreviation for circa).
'tinned food?' becomes 'anny' (I can't justify this - if you can you should believe this answer much more).
'c'+'anny'='CANNY'
Can you help me to learn more?
(Other definitions for canny that I've seen before include "Shrewd, knowing" , "Fly" , "Shrewd, clever" , "Shrewd like Scotsman" , "Worldly-wise" .)