Boundless, as story no one's heard? (6)
I believe the answer is:
untold
'boundless' is the definition.
(I've seen this in another clue)
'story no one's heard?' is the wordplay.
I cannot really understand how this works, but
'no' could be 'o' (O resembles 0) and 'o' is found within the answer.
'one' could be 'un' (northern English dialect form of 'one') and 'un' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'as' acts as a link.
Can you help me to learn more?
(Other definitions for untold that I've seen before include "enormous" , "Too many to be counted; not narrated" , "like a kept secret?" , "Not disclosed - fabulous!" , "Not narrated or measured" .)