butt in
Definitions
To interrupt a conversation or activity without being invited.
To interfere or meddle in someone else's affairs.
Examples
I wish he would stop trying to butt in on our private conversations.
It is considered rude to butt in when two people are already speaking.
She always manages to butt in with her opinion, even when nobody asked for it.
Synonyms
interrupt intervene intrude interfere barge in meddle obtrude