Old estate for growing has no end of disinvestment? This makes things clear (11)
I believe the answer is:
'estate for growing has no end of disinvestment? this makes things clear' is the definition.
The definition suggests a singular noun which matches the answer.
'old' is the wordplay.
I cannot quite understand how this works, but
'old' could be 'ex' (prefix meaning former or onetime) and 'ex' is present in the answer.
The remaining letters 'planation' 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 explanation that I've seen before include "Statement making something clear" , "That which makes meaning clear" , "Justification for an action or belief" , "Reason or justification (for something)" .)