What is the origin of lucubrate?

Lucubrate derives from the Latin verb lūcubrāre “to work at night” or, more specifically, “to work by candlelight/lamplight,” from the Proto-Indo-European root lewk- “light,” which is the source of many Latin-derived words related to light, clarity, and brightness. From the verb lūcēre “to shine,” we inherit lucid and translucent; from the verb lūstrāre “to make bright,” we have adapted luster and illustrate; and from the noun lūmen “light,” we have luminous and illuminate. This Proto-Indo-European root is also found in the English terms light and lea, another word for “meadow”; Latin lūna “moon”; and Ancient Greek leukós “white,” as in leukocyte, the technical term for a white blood cell. Lucubrate entered English in the early 1600s.