What does "butt in" mean?

To join a conversation or situation in which one is not welcome or invited; to interject (connotes a rude or discourteous interruption).

What is a synonym for "butt in"?

Common synonyms include: barge in, barge in, barging, blow it, break in, break in.

verb, slang

verb, slang ·Moderate ·High school level

Verb

1
To join a conversation or situation in which one is not welcome or invited; to interject (connotes a rude or discourteous interruption). idiomatic, informal
"Hey, this is none of your business; don’t butt in!"
2
break into a conversation wordnet
3
To join a queue not at the end, but in the middle. transitive

"Hey, this is none of your business; don’t butt in!"