torpor \ ˈtȯr-pər \ noun
1. a state of motor and mental inactivity with a partial suspension of sensibility
2. inactivity resulting from lethargy and lack of vigor or energy
The word torpor has appeared in 18 articles on NYTimes.com in the past year, including on Sept. 8 in “These Hummingbirds Take Extreme Naps. Some May Even Hibernate” by Veronique Greenwood:
Hummingbirds live a life of extremes. The flitting creatures famously have the fastest metabolisms among vertebrates, and to fuel their zippy lifestyle, they sometimes drink their own body weight in nectar each day. But the hummingbirds of the Andes in South America take that extreme lifestyle a step further.
Not only must they work even harder to hover at altitude, but during chilly nights, they save energy by going into exceptionally deep torpor, a physiological state similar to hibernation in which their body temperature falls by as much as 50 degrees Fahrenheit. Then, as dawn approaches, they start to shiver, sending their temperatures rocketing back up to 96 degrees.