waterhole

Meaning

Noun

• A depression in which water collects, especially one where wild animals come to drink.
• A watering hole; a place where people meet to drink and talk.
• A part of the electromagnetic spectrum, between the regions where hydrogen and hydroxyl radiate, that is relatively quiet in terms of radio astronomy.

Origin

• water + hole.
• Coined by Bernard Oliver in 1971, in allusion to the idea that this part of the spectrum would be that used by extraterrestrial intelligence to communicate.