probe

Any of various medical instruments used to explore wounds, organs, etc.

Something which penetrates something else, as though to explore; something which obtains information.

An act of probing; a prod, a poke.

An investigation or inquiry.

A tube attached to an aircraft which can be fitted into the drogue from a tanker aircraft to allow for aerial refuelling.

A small device, especially an electrode, used to explore, investigate or measure something by penetrating or being placed in it.

A small, usually unmanned, spacecraft used to acquire information or measurements about its surroundings.

(game of go) a move with multiple answers seeking to make the opponent choose and commit to a strategy

Any group of atoms or molecules radioactively labeled in order to study a given molecule or other structure