Warden's joint needs protection (11)
I believe the answer is:
stewardship
'protection' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'warden's joint' is the wordplay.
'warden's' becomes 'stewards' (I am not sure about this - if you are sure you should believe this answer much more).
'joint' becomes 'hip joint' (part of body).
'stewards'+'hip'='STEWARDSHIP'
'needs' acts as a link.
Can you help me to learn more?
(Other definitions for stewardship that I've seen before include "Management or care (of something)" , "Management of somebody else's property" , "Job for resigned MP" , "Administration of property, finance etc" .)