They are actually called cigarette butts, and they are the white part on the end of a cigarette, hence the name butt.
The end of a cigarette, or the cigarette butt in America.
That is just a slang word. Butt is a common word that just means "end," like the end of a cigarette or a rifle. So the back end of the body, and the word hole makes it more specific that you mean the opening. Thus the opening in the back of the human body.
A "dog end" is a British term for the leftover or stub end of a cigarette that has been smoked. It is often discarded as waste.
A stale cigarette. A stale cigarette has no taste whatsoever.
Cigarette Pack Collector.
Small leftover pieces of cigarette are called cigarette butts.
Sidestream Smoke. More than half the pollutants emitted by a cigarette come not from the smokedend of the cigarette but from its other end - the cigarette's burning end - and are called sidestream smoke.
Back of a boat is called stern and Bow is the front of a boat.
Small leftover pieces of cigarette are called cigarette butts.
The butt
If I correctly understand what you're asking, that would be called secondhand smoke.