The end of an already used cigarette.

Got the covid-19 vaccine

The stump of a cigarette, usually there is a small amount of tobacco still to be smoked upon it.

Cigarette butt.

a dog end is the tastiest part of a cigarette as far as most tramps in nottingham are concerned. to find one a tramp, someone like my mate the freak, would go to a bus station or hospital and wait like a vulture for every dog end of every smoker around. people like this get millions of pounds in benefits each week but they never buy cigarettes just fag papers to roll up their latest dirty nubs

Meaning the rear end of a dog. Often used towards a dirty undesirable person or someone you find hideously ugly. It is usually a male saying towards a female's looks. It is said on its own as well as being used in a sentence.

A descriptive phrase for the purpose of implying someone is bad at something or has just performed something badly. Similar to useless