Soldier dropping in? (4)
I believe the answer is:
para
'soldier' is the definition.
(paratrooper)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for para that I've seen before include "Airdropped soldier" , "High-jumper" , "abbreviated passage having unity" , "Soldier in an airborne unit" , "Soldier (shortened)" .)