One getting high from, and later coming down on, H? (7)
I believe the answer is:
chopper
This clue could be a double definition.
'one getting high from' is the first definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'later coming down on h?' is the second definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'and' is the link.
Can you help me to learn more?
(Other definitions for chopper that I've seen before include "Blade" , "An informal helicopter, or an axe" , "Air transport" , "Motorbike" , "Small axe" .)