n. [ L. interrogatio: cf. F. interrogation. ] [ 1913 Webster ]
1. The act or process of interrogating or questioning; examination by questions; an instance of interrogating; inquiry. [ 1913 Webster ]
2. A question put; an inquiry. [ 1913 Webster ]
3. A point, mark, or sign, thus [ ? ], indicating that the sentence with which it is connected is a question. It is used to express doubt, or to mark a query. Usually called a question mark; called also interrogation point. [ 1913 Webster +PJC ]
☞ In works printed in the Spanish language this mark is not only placed at the end of an interrogative sentence, but is also placed, inverted [ as thus (¿) ], at the beginning. [ 1913 Webster ]