Sally's unwelcome visit (4)
I believe the answer is:
raid
This might be a double definition.
'sally's' is the first definition.
(both can mean a military attack)
'unwelcome visit' is the second definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps there's an association between them I don't understand?
Can you help me to learn more?
(Other definitions for raid that I've seen before include "Maraud" , "Smash-and-grab?" , "Search by police without warning" , "Foray, sudden attack" , "Inroad" .)