A cistern adapted as a container for food (8)
I believe the answer is:
canister
'a container for food' is the definition.
I can't tell whether this definition defines the answer.
'a cistern adapted' is the wordplay.
'adapted' indicates an anagram.
'a'+'cistern'='acistern'
'acistern' with letters rearranged gives 'CANISTER'.
'as' acts as a link.
Can you help me to learn more?
(Other definitions for canister that I've seen before include "Jar (of e.g. tea, sugar)" , "Metal container, for tea say" , "Metal case" , "Metal container for storing dry foods" , "Metal food container" .)