Incontinent men receiving treatment for inability to retain things (7)
I believe the answer is:
amnesia
'things' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'incontinent men receiving treatment for inability to retain' is the wordplay.
I cannot really see how this works, but
an anagram of 'men' is 'mne' which is located in the answer.
The remaining letters 'asia' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for amnesia that I've seen before include "Asia men with memory loss (7)" , "Partial or total loss of memory" , "As a mine (anag)" , "memory problem" , "Completely forgetting" .)