A situation of serious and immediate danger.
An event which causes a loss, or the risk of a specific such event.
Something that causes, contains, or presents danger.
To cause to be in danger; to imperil; to risk.
Systematic observation of places and people by visual, aural, electronic, photographic or other means.
Continuous monitoring of disease occurrence for example.
Close observation of an individual or group; person or persons under suspicion.
In criminal law, an investigation process by which police gather evidence about crimes, or suspected crime, through continued observation of persons or places.