Why a name is, perhaps, forgotten (7)
I believe the answer is:
amnesia
'why' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'a name is perhaps forgotten' is the wordplay.
'perhaps' indicates anagramming the letters.
'forgotten' becomes 'a' (I am not sure about this - if you are sure you should believe this answer much more).
'name'+'is'='nameis'
'nameis' with letters rearranged gives 'amnesi'.
'amnesi'+'a'='AMNESIA'
Can you help me to learn more?
(Other definitions for amnesia that I've seen before include "Pathological forgetfulness" , "Seaman I found in state of memory loss" , "Seaman I find suffering from memory loss" , "Is a name (anag.)" , "Partial or total loss of memory" .)