Short for Desert Eagle a type of pistol
hit em with the dezi
It is usually the nickname of Désiré, Désire, Desiré, Désirée, Desirée, Désiree, Desire, Desiria and really any associated name. Other associated nicknames are ray/rayray/ré you get the point.
He: Hi I'm Dan, pleased to meet you.
She: Hi I'm Désiré but friends call me Dezi