An ape comprehends the treetops (6)
I believe the answer is:
canopy
'treetops' is the definition.
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for canopy that I've seen before include "Uppermost branches of forest trees" , "Covering over four-poster, etc" , "Hanging cover forming shelter over bed or throne" , "Ceremonial covering" , "Hanging cover over bed, shopfront, etc" .)