Indescribable aunty unwrapped antique (6)
I believe the answer is:
untold
'indescribable' is the definition.
(I've seen this before)
'aunty unwrapped antique' is the wordplay.
'unwrapped' means to look at the middle letters (the letters which wrap the word are removed).
'antique' becomes 'old' (similar in meaning).
The centre of 'aunty' is 'unt'.
'unt'+'old'='UNTOLD'
(Other definitions for untold that I've seen before include "extensive" , "Countless" , "like a kept secret?" , "Unspoken - inexpressible - uncounted" , "enormous" .)