Reasonable rations seen halved and reallocated (11)
I believe the answer is:
commonsense
'reasonable' is the definition.
(similar in meaning)
'rations seen halved and reallocated' is the wordplay.
I cannot really understand how this works, but
an anagram of 'seen' is 'ense' which is located in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found in the answer.
The remaining letters 'commos' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for commonsense that I've seen before include "Nous" , "gumption" .)