Noctilucy

(n.) moonlight

The fact that moonlight was known as noctilucy in seventeenth century English proved popular this week on HH.

Noctilucy—an entry from Henry Cockeram’s 1623 English Dictionarie—is an anglicized version of the Latin noctiluca, which as well as meaning “moon” or “moonlight” was also used of lanterns, fireflies, and other phosphorescent creatures.

In fact, when it was first borrowed into English way back in the fourteenth century, noctiluca was also used to refer to a glow-worm or firefly, and even today the word remains the taxonomic name for a genus of bioluminescent marine creatures.