Organic coating beats fossil fuel (7)
I believe the answer is:
topsoil
'organic coating' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'beats fossil fuel' is the wordplay.
'beats' becomes 'tops' (both can mean to outdo or better).
'fossil fuel' becomes 'oil' (I've seen this in another clue).
'tops'+'oil'='TOPSOIL'
Can you help me to learn more?
(Other definitions for topsoil that I've seen before include "where grass grows" , "Upper layer of earth" , "Garden's surface layer" , "Earth's surface" , "best part of earth" .)