Our airmen go up a lot (3)
I believe the answer is:
far
'a lot' is the definition.
Both the definition and answer are adverbs. Maybe there's a link between them I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for far that I've seen before include "Distant" , "Very much" , "At a great distance way" , "A long, long way to go" , "Remote" .)