Petronas and Exxon initially put fish back to get source of oil (6)
I believe the answer is:
peanut
'oil' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for peanut that I've seen before include "Singularly little money" , "Ante up for the popular kernel" , "Ante up for this type of hard fruit" , "Bar nibble" , "Something to eat" .)