In the American motion picture industry, wide release refers to a motion picture that is playing nationally (as opposed to a few cinemas in cities such as New York and Los Angeles). Specifically, a movie is considered to be a wide release when it is in 600 theatres or more in the United States and Canada.
In the U.S., films holding an NC-17 rating have almost never received wide releases. Showgirls (1995) is the only film with an NC-17 rating to get one.
The term is sometimes used informally in relative terms. For example, a documentary or art film promoter might speak of a film expanding from a few New York and Los Angeles screens to cinemas in major cities across the U.S.A. as moving into "wide release" although it might be playing on single screens in as few as 15 or 20 major cities.