(US, idiomatic) The path slaves took to deliver food from the kitchen building of a plantation to the main dining room. Stories claim that slaves were expected to whistle during this walk in order to assure their masters that they were not eating the food.

Alternative form of whistle-blower

(idiomatic, usually with "on") To disclose information to the public or to appropriate authorities concerning the illegal or socially harmful actions of a person or group, especially a corporation or government agency.

One who reports a problem or violation to the authorities; especially, an employee or former employee who reports a violation by an employer.

(US, regional) The woodchuck.

(idiomatic, Southern US) To engage in idle conversational fantasies.

A tin whistle.

A high-pitched whistle, inaudible to humans, used to train dogs. / (figuratively) That which is understood only by a narrow demographic.

The action of a whistleblower.

(idiomatic) A small train station. / (politics) A brief stop on a campaign tour to make a speech or perform some other type of public electioneering.