1. An acronym for "yes in my back yard," an expression of support for some development or change proposed for one's immediate area. The term is the opposite of "NIMBY" ("not in my back yard"), a clichéd expression of opposition to such a development or change, based on the opinion that it will have a negative impact on one's home or local surroundings. As more homeowners realize the benefit of having mixed-use developments nearby, you'll see a lot more people saying "YIMBY" instead of "NIMBY."

2. Someone who espouses such views. YIMBYs seem to be popping up all over in response to housing shortages and skyrocketing rents in this city.