To try to discover information that other people do not want you to know, by asking questions carefully and not directly. (Cambridge Dictionary)
To examine something with a tool, especially in order to find something that is hidden. (Cambridge Dictionary)
A blunt-ended surgical instrument used for exploring a wound or part of the body. (Oxford Dictionaries)
A small device, especially an electrode, used for measuring, testing, or obtaining information. (Oxford Dictionaries)
A thorough investigation into a crime or other matter. (Oxford Dictionaries)
If you probe into something, you ask questions or try to discover facts about it. (Collins Dictionary)
A slender medical instrument used especially for exploration (as of a wound or body cavity) (Merriam – Webster)
Definition of probe by The Free Dictionary.
Space probe. Wikipedia.