One object of retirement (5)
I believe the answer is:
sleep
'retirement' is the definition.
The answer and definition can be both states of affairs as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'one object' is the wordplay.
'one' becomes 'slee' (I am not sure about this - if you are sure you should believe this answer much more).
'object' becomes 'P' (P is an example).
'slee'+'p'='SLEEP'
'of' is the link.
Can you help me to learn more?
(Other definitions for sleep that I've seen before include "Shut-eye" , "Snooze" , "Doze, nap" , "crash" , "''... that knits up the ravell'd sleeve of care'' (Macbeth)" .)