The cigarette butt is the indicator of the fact that there is something in your life that is very old and no longer useful. The dream shows that there is some situation or person in your waking life that makes you feel this way. The cigarette butt could also signify that you finished something unpleasant in your life.
Dream dictionary: butt dream meanings
…Your own is a sign of hypocrisy and betrayal. A woman’s butt cheeks indicate repressed desires….
Seeing the butt of a gun announced oppositions and rivalries. Having it, authority to defend your interests.