Burrowing into hill is very daring (5)
I believe the answer is:
brave
'daring' is the definition.
(I've seen this before)
'burrowing into hill is very' is the wordplay.
I cannot really see how this works, but
'very' could be 'v' (common abbreviation) and 'v' is present in the answer.
'hill' could be 'brae' (Scottish term for a hill) and 'brae' is found within the leftover letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for brave that I've seen before include "Intrepid and fearless" , "Showing courage" , "Indian warrior" , "Egg-shaped" , "Hardy" .)