One of the reasons it's hard to tell by context clues what racketeering is is because it actually is a pretty vague term involving all sorts of organized crime. The root of the word is "racket", which is an illegal business. Taking part in an illegal business is called "racketeering".
But what makes a business illegal? All sorts of things! Bribery, counterfeiting, embezzlement, extortion, obstruction of justice, money laundering, trafficking of stolen goods, etc etc etc.
So I think what makes a crime "racketeering" is that it's attached to a business, and it's typically part of an organized crime ring. The term was first used in 1927 to refer to the criminal acts of the Chicago Teamsters union.