Very worried after a force skips attack (4)
I believe the answer is:
raid
'attack' is the definition.
(raiding is a kind of attacking)
'very worried after a force skips' is the wordplay.
I cannot really understand how this works, but
'a' is within the answer.
The remaining letters 'rid' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
(Other definitions for raid that I've seen before include "A sudden military attack and withdrawal" , "Invade" , "Maraud" , "Assault, attack" , "military operation" .)