Probe  —n. 1 penetrating investigation. 2 small device, esp. An electrode, for measuring, testing, etc. 3 blunt-ended surgical instrument for exploring a wound etc. 4 (in full space probe) unmanned exploratory spacecraft transmitting information about its environment. —v. (-bing) 1 examine or enquire into closely. 2 explore with a probe. [latin proba: related to *prove]