E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Private information, secret warning. In horse-racing, it means such secret information as may guide the person tipped to make bets advantageously. A straight tip comes straight or direct from the owner or trainer of the horse in question. A man will sometimes give the police the tip, or hint where a gang of confederates lie concealed, or where law-breakers may be found. Thus, houses of ill-fame and keepers of clandestine gaming houses in league with the police, receive the tip when spies are on them or legal danger is abroad.
If he told the police, he felt assured that the tip would be given to the parties concerned, and his efforts would be frustracted.Mr. Steads defence, November 2nd, 1885.
He gave me a tipa present of money, a bribe. (See DIES.)