Ration is entirely too much keeping crew (9)
I believe the answer is:
allotment
'ration' is the definition.
(I've seen this in another clue)
'entirely too much keeping crew' is the wordplay.
'entirely' becomes 'all' (I've seen this in another clue).
'too much' becomes 'OTT' (short for over the top).
'keeping' means one lot of letters goes inside another.
'crew' becomes 'men' (both can mean staff or employees).
'ott' enclosing 'men' is 'otment'.
'all'+'otment'='ALLOTMENT'
'is' acts as a link.
(Other definitions for allotment that I've seen before include "Plot for cultivation" , "Distribution of shares" , "Vegetable plot" , "Where vegetables may be produced" , "Rented garden plot" .)