Ration (9)
There are a few possibilities for this:
allowance
'ration' is the definition.
(allowance is a kind of ration)
This is the entire clue.
(Other definitions for allowance that I've seen before include "Portion, ration" , "Fixed sum given regularly" , "Pocket money" , "Permissible difference or amount" , "income" .)
'ration' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for allot that I've seen before include "Ration" , "Assign (to someone)" , "appropriate" , "Apportion, share" , "Allocate" .)
'ration' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for quota that I've seen before include "Share to which one is entitled" , "certain allowance" , "Prescribed number or quantity permitted" , "Proportional share" , "Regulated number" .)
'ration' is the definition.
(a ration is a share of a limited resource)
This is the entire clue.
(Other definitions for share that I've seen before include "Portion, allotment" , "Distribute" , "Allotted portion" , "Have part-ownership" , "hand pieces out" .)