Reason to limit beer consumption (9)
I believe the answer is:
rationale
'reason' is the definition.
(I've seen this before)
'limit beer consumption' is the wordplay.
'limit' becomes 'ration' (rationing is a kind of limiting).
'beer consumption' becomes 'ale' (I am not sure about this - if you are sure you should believe this answer much more).
'ration'+'ale'='RATIONALE'
'to' is the link.
Can you help me to learn more?
(Other definitions for rationale that I've seen before include "Logical reason for action" , "solution in theory" , "grounds?" , "justification" , "Logic, reasoning" .)