Natural environment welcoming check on energy (9)
I believe the answer is:
ecosystem
'natural' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'environment welcoming check on energy' is the wordplay.
'environment welcoming' becomes 'cosy' (I can't justify this - if you can you should believe this answer much more).
'check' becomes 'stem' (both can mean to control or stop).
'on' is a charade indicator (letters next to each other).
'energy' becomes 'e' (physics symbol as in E=mco).
'cosy'+'stem'='cosystem'
'cosystem' after 'e' is 'ECOSYSTEM'.
Can you help me to learn more?
(Other definitions for ecosystem that I've seen before include "orderly collection of organisms" , "The interaction of a group of organisms with their physical environment" , "Community of organisms and their environment" , "integrated community" , "Biological community with its environment" .)