butts

To hit or push something forcefully with the head or horns, as an animal does.

"The ram often butts the gate with its head."

The discarded, unsmoked ends of cigarettes or cigars, often found as litter.

"There were cigarette butts all over the pavement."

To rudely interrupt a conversation or activity without being invited to do so.

"He always butts in with his unwanted opinions."