Citizenry means all the citizens of a town, a country, or a state, taken as one group — not this person or that person, but everyone who belongs there. You meet it in news, speeches, and rather formal writing: “the citizenry voted,” “a well-informed citizenry.” Everyday talk usually just says the people or the citizens. It names the whole body of people who have that belonging, a bit like the public, though actually it is tighter than the public: visitors and people passing through are not in the citizenry. It is not the legal paper or the status of being a citizen (that is citizenship), and it is not a fancy word for city.