To Mirandize is to inform an arrested suspect of his or her rights. The word derives from the Miranda v. Arizona U.S. Supreme Court ruling, which held that self-incriminating statements made by a crime suspect are not admissible in court unless the suspect is first informed of his or her rights to silence and legal counsel. The verb started as law-enforcement jargon, but it now appears elsewhere.
Some usage authorities frown on Mirandize, advocating instead phrases such as read him his Miranda rights and inform her of her right to legal counsel. But Mirandize (usually capitalized, but this may someday change) is a brief and useful, if informal, alternative to these wordy phrases, and it is now a part of the language no matter what the usage authorities say.
Mirandize is an American word. The court ruling obviously doesn’t apply to other countries, so the word is unlikely to catch on anywhere else.
Examples
In a statement, several GOP lawmakers … called the decision not to immediately Mirandize Tsarnaev “sound and in our national security interests.” [CBS News]
[T]he Supreme Court has created numerous exceptions to the Miranda warnings, resulting in many un-Mirandized statements being legally admitted into evidence. [Encyclopedia of Contemporary American Social Issues, Michael Shally-Jensen]
She was Mirandized and admitted to having the substance in her pants pocket. [Gant Daily]
The leftwing demon-crats have called for mirandization of terrorists, and have opposed EITs and water-boarding. [comment on The Heritage Foundation]
[T]he police have always had the power to question a suspect about imminent threats without Mirandizing him. [Guardian]