A (somewhat racist) term used by white people when they want to access information on an african-american by way of another african-american friend. Said whities usually blindly assume the friend knows all black people.
Whitie 1: What is Monique's number?
Whitie 2: I don't know, let me access my negrodex *calls random black friend*.
A white person who is sexually attracted to or amorously involved with a so-called Negro; usage circa 1960s.
Etymology: The word was current in the early to mid-1960s, before the black power movement replaced the word "Negro" with "Afro-American" and "Black" in polite conversation. The word is featured in the title of Guy D. St. Lazare's 1966 pulp novel "The Young Negrosexuals".