Foliage doesn't stay (6)
I believe the answer is:
leaves
'foliage' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for leaves that I've seen before include "Pulls out < sheets" , "takes off" , "spinach for example" , "Abandons" , "Departs or bequeaths" .)