Moondial

Part of speech: noun

Definitions

1. A time-measuring device that determines hours by observing the moon's position and brightness in the sky at night
2. A mechanism used to indicate time by analyzing the moon's location and luminosity in the night sky to establish hours
3. An instrument that tells time by tracking the moon's brightness and position during the night

Etymology: A moondial is a compound of "moon" and "dial", built on the model of "sundial", the older device that tells time by the position of the sun's shadow on a marked face. The pattern is simple: a sundial reads the sun, so a device that tells time by the moon takes the moon as its source, with the same dial-and-shadow idea carried over. Because the word is formed transparently from two plain English elements, its meaning is clear from its parts, and it works as a playful coinage for a timekeeping device rather than a term with a long technical history.

Synonyms: moon dial