"plant of the genus solanum," with white flowers and black poisonous berries, Middle English night-shade, from Old English nihtscada, literally "shade of night," perhaps in allusion to the berries; see night + shade (n.). A common Germanic compound, cognates: Dutch nachtschade, German Nachtschatten.
c. 1400, "point at which the sun crosses the earth's equator, making day and night of equal length everywhere," from Old French equinoce (12c.) or directly from Medieval Latin equinoxium "equality of night (and day)," from Latin aequinoctium, usually in plural, dies aequinoctii "the equinoxes," from aequus "equal" (see equal (adj.)) + nox (genitive noctis) "night" (see night). The Old English translation was efnniht. Related: Equinoctial.
"account of what passes in the night," the converse of a diary, 1714; as though from Latin *noctuarius; see noct- "night." A word in use 18c.-19c.
1620s, "to work at night," from Latin lucubratus, past participle of lucubrare "work at night, work by lamplight," from the stem of lucere "to shine" (from PIE *louk-eyo-, suffixed (iterative) form of root *leuk- "light, brightness"). Hence "to write or study laboriously" (1804).