One causing damage in V&A close to fanatical (6)
I believe the answer is:
vandal
'one causing' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'damage in va close to fanatical' is the wordplay.
'damage' becomes 'and' (I can't explain this - if you can you should believe this answer much more).
'in' is an insertion indicator.
'close to' suggests the final letters (the close of something is the end).
The final letter of 'fanatical' is 'l'.
'and' inserted into 'va' is 'vanda'.
'vanda'+'l'='VANDAL'
Can you help me to learn more?
(Other definitions for vandal that I've seen before include "Hoodlum" , "Ger. tribesman; one who damages property" , "Someone who wilfully damages property" , "Wanton wrecker" , "One who maliciously causes damage" .)