Inability to remember a name is maddening (7)
I believe the answer is:
amnesia
'inability to remember' is the definition.
(I've seen this before)
'a name is maddening' is the wordplay.
'a name is' can be anagrammed to 'AMNESIA'.
Though, I'm not sure how this is indicated.
Can you help me to learn more?
(Other definitions for amnesia that I've seen before include "Is a name (anag.)" , "Severe forgetfulness" , "Clinical loss of memory" , "Failure to recall" , "As a mine (anag)" .)