Noun

(en noun)

Close observation of an individual or group; person or persons under suspicion.

Continuous monitoring of disease occurrence for example.

(military, espionage) Systematic observation of places and people by visual, aural, electronic, photographic or other means.

* {{quote-magazine, date=2012-12-14

, author=Simon Jenkins, authorlink=Simon Jenkins , title=We mustn't overreact to North Korea boys' toys , volume=188, issue=2, page=23 , date=2012-12-21 , magazine= citation , passage=The threat of terrorism to the British lies in the overreaction to it of British governments. Each one in turn clicks up the ratchet of surveillance , intrusion and security. Each one diminishes liberty.}}

(legal) In criminal law, an investigation process by which police gather evidence about crimes, or suspected crime, through continued observation of persons or places.

Noun

(en noun)

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

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

An act of probing; a prod, a poke.

(figuratively) An investigation or inquiry.

They launched a probe into the cause of the accident.

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

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

Insert the probe into the soil and read the temperature.

(astronautics) 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