A girl who unrelentlessly offers her butt to guys when ever she has the chance. But when it's time for action, she refuses to take it in the box. Just the butt.
A type of smoker (normally of taylored cigarettes, but can include rolled tobacco, and marijuana joints) who drains the cigarette all the way to the butt, not wasting even a little. It is a derogatory term and usually has association with those of lower socio-economic backgrounds.
God, don't be such a butt slut! I'll give you another cigarette, geez!