Our inn - it’s upset, getting unwelcome visit (9)
I believe the answer is:
intrusion
'unwelcome visit' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Maybe there's an association between them I don't understand?
'our inn it's upset' is the wordplay.
'upset' indicates an anagram.
'our'+'inn'+'its'='ourinnits'
'ourinnits' is an anagram of 'INTRUSION'.
'getting' is the link.
Can you help me to learn more?
(Other definitions for intrusion that I've seen before include "Encroachment" , "Uninvited presence" , "Something entering undesirably" .)