He makes one leave the air terminal (4)
I believe the answer is:
igor
'he' is the definition.
'one leave the air terminal' is the wordplay.
'one' becomes 'i' (Roman numeral).
'leave' becomes 'go' (to go is to depart or leave).
'terminal' indicates one should take the final letters (the final or terminal letter).
The last letter of 'air' is 'r'.
'i'+'go'+'r'='IGOR'
'makes' acts as a link.
(Other definitions for igor that I've seen before include "Hero of Borodin" , "Prince of grand opera" , "Stravinsky, perhaps" , "Prince in Borodin's opera" , "Stravinsky, for example" .)