A spot for a vertical descent (4)
I believe the answer is:
drop
This clue could be a double definition.
'a spot' is the first definition.
(I know that drop is a type of hiding place)
'vertical descent' is the second definition.
'drop' can be an answer for 'descent' (drop is a kind of descent). I am unsure of the 'vertical' bit.
'for a' is the link.
Can you help me to learn more?
(Other definitions for drop that I've seen before include "Finish with" , "Fall; delivery" , "Desert" , "Not a lot of water" , "Small bit - fall" .)