melefar, "veil-glow"
The light of the galaxy as seen from the surface of the world on a dark night. Easiest to see on the throneworld, which has a single moon, than on the other worlds with their varied cosmic bodies (third world, in particular, has no moon at all but a ring of dust that makes it nigh-impossible to see the galaxy's veil; this ring of dust is known informally as the Arvarnari, the "halo" or "corona," from the more formal name used by astronomers, arvarnari jzilni, "the halo of the world.")
Historically, the celestial bodies have been of great interest to the Ai-Naidar, and when astronomy was new cities of sufficient size developed customs based on observing those bodies. Astronomers, newly-instated into the formal ranks of the Public Servant caste, were eager to do science while remaining in the company of other Ai-Naidar (a must for the species) and near their patrons above the Wall of Birth. To facilitate their observations, the city's ruling Noble or Regal would require all artificial lights be off (or lit only in cellars; these cellars quickly developed a history of their own) by a certain hour.
What began as scientific necessity became local culture. Cities with lights-out customs began to associate the dark period with contemplation, as if the entire city was pausing between breaths, and its people with it. Called meleshol, a portmanteau of the word for veil-glow and the word for breathpause ("shol"), the lights-out time became associated with intimacy, philosophy and meditation. Ai-Naidar speak of makadled melesholi, the kind of knowledge one can only absorb while free of excess stimulation, or of pad melesholi, the receptive and restful mental state brought about by turning off the lights and accepting the cessation of activity.
"There is something about being awake and yet in the dark, knowing that the work must be set aside in favor of an inner stillness," wrote one Public Servant philosopher. "The mind turns outward and upward, toward the beauty outside oneself. It considers it with grace and deliberation; it is nourished; it is relaxed. This quality of mind cannot be duplicated in any other fashion."
In the modern age, there are cities that observe meleshol despite having no observatory: their customs began when news of meleshol traveled from elsewhere and the locals decided to adopt it. Other cities observe it on a schedule: once a week, once a month, or in accordance with the rising and falling of specific celestial bodies. Some cities observe it only as a holiday, once a year. And some cities not at all. The customs are old enough now that it is rare that any city changes its ways. A visitor can tell immediately whether a city observes meleshol and how often by its glyph, usually set on stones in city walls (interior and exterior), on pavers or on pylons in busy intersections. The glyph features a crescent moon in cities that observe meleshol, and dates or numbers beneath it for how often/when; or a sun for cities that are "lights-free," (called informally tansha cities, a very lazy derivation from the original word for "sunlit," tanshani; tansha has since come to mean "shiny").
Strangers or visitors are expected to observe the local custom. Those sufficiently moved by the experience can usually find someone to sell them a meleshol token, a form of souvenir common to cities that observe lights-out. These usually take the form of some kind of ceramic or porcelain pendant with the crescent moon glyph and the city's emblem. There have been Ai-Naidar who make it a point to go to every city they know of that observes meleshol specifically to collect them. These people are called meleshol vekka, or "lights-out pilgrims." Once a respectable term applied to people searching for some inner quiet, this term has since come to describe someone who wants to have the virtues of an accomplished "lights-out" meditator—someone who has internalized that inner stillness—without actually having cultivated those virtues.
Public Servant linguists are currently debating whether the word pilgrim now should be considered equivalent to the word for tourist. But that is a story for another day.