Big Apple
Although the history of "Big Apple " was once thought a mystery, a clearer picture of the term's history has emerged due to the work of amateur etymologist Barry Popik, and Gerald Cohen of Missouri University of Science and Technology. A number of false theories had previously existed, including a claim that the term derived from a woman named Eve who ran a brothel in the city. This was subsequently exposed as a hoax.
Big Apple
The term "big apple" was used by Frank Sinatra in conversation with opera singer Dorothy Kirsten on an episode of the NBC radio program "Light Up Time" on March 28, 1950.