This is how people who are no longer hip but also not stuck-up assholes refer to the person they're engaged to. "Fiansizzle" is an accepted variant spelling.
Man in line at grocery store to other fellows also in line: "Hey daddios, any of you crazy cats got dibs on that hep dolly over there?" Another man in line: "I do. She is my fiancizzle."
by Bob-e. G. August 26, 2017