Aerodynamic force (4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
drag
'aerodynamic force' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for drag that I've seen before include "Trail along the ground" , "Transvestite's garb" , "Pull against a resistance" , "Bind" , "pain" .)