Broadway Illumination is a term used to describe the NEON lights that line the streets of Broadway in New York City. The term can also refer to the bright and colorful signs that adorn the theaters and other buildings along the street. The crossword solution for this term is 'NEON', which is an acronym for 'NEON Electric Outdoor Network'. NEON lighting has been used since the early 1900s to create bright and eye-catching displays, and it is still used today to light up Broadway and other areas of the city.