1. [Astronomy]. The point of the celestial sphere directly opposite the zenith and directly below the observer.
2. The lowest point; the time of greatest depression or adversity.
At the nadir of every recession, business pages fill up with stories of belt-tightening families who move to Vermont and buy their food in bulk.
– Peter T. Kilborn, “Splurge“, New York Times, June 21, 1998