horn in

(slang, dated) To kick out, expel or reject.

(UK, informal, often used with "on") To intrude; butt or muscle in ; to be nosy.

Dated slang meaning to kick someone out, expel them, or reject them decisively — to give someone the horn and show them the door. It implies a forceful and final removal rather than a gentle suggestion to leave. The term feels like it belongs to a particular era of American or British informal speech, more at home in a mid-century novel than a modern conversation, but it has a satisfying bluntness that keeps it useful when you want to describe being forcibly removed from somewhere.

To intrude or interrupt.

(slang, transitive) To enter or join (something) aggressively and without an invitation.