A contraction of His Honor. Not city-centric, but used regularly in New York City newspapers, usually to set an informal tone about a public official.
"Hizzoner would have none of it."
In Detroit, a sarcastic reference to Kwame Kilpatrick, the man who dubbed himself the "hip hop mayor."
May also be used to describe others who bring a "ghetto" or low class ethos to an otherwise-esteemed position, particularly in government.
It was recently disclosed that other cities' police forces refuse to guard Hizzoner after hours because of his unethical behavior.