(US, law) The authority that a United States federal court has to hear a cause of action brought under the United States Constitution or federal statutes.

(television, radio) During a classroom quiz or game show, a question posed to two or more opponents where both are able to answer by signaling, and depending on the rules, the one that responds with a correct answer either takes control of the game or proceeds to advance to a subsequent round.

(figuratively) A question that is very important and/or difficult to answer.

Alternative form of million-dollar question

Used to encourage people to seek knowledge by asking questions, no matter how silly the questions may appear to be.

Alternative spelling of chicken-or-egg question

(logic, philosophy) A supposed paradox concerning whether chickens or chicken eggs existed first. / (logic, philosophy) A question to decide which of two interdependent things happened first.

The punctuation mark "¿", which is placed at the beginning of questions in Spanish and, less commonly, Catalan.

plural of inverted question mark

(rhetoric) A question that presupposes some controversial premise, such that it cannot be directly answered without incriminating oneself or, at least, unintentionally conceding a point; a loaded question.