night letters

Noun

night letter (plural night letters)

1. (historical) A telegram sent overnight at a reduced rate for delivery on the morning of the following day, typically with a minimum charge for 25 words or less.
   • "Someone named Rose sent a night letter from Philadelphia asking for six free tickets. A relative?"1976, [Walter Wager], My Side by King Kong: As Told to Walter Wager, New York, NY: Collier Books, page 104

   Synonyms:

   NL

2. An unsigned leaflet distributed clandestinely.
   • Until one night this October, when members of Echo Company, from the Second Battalion, Fourth Marines […] quietly sneaked into Juz Ghoray and posted signs on people’s doors and windows. Their idea was to co-opt the infamous Taliban practice of intimidating government sympathizers with night letters...2012 February 1, Luke Mogelson, “The Hard Way Out of Afghanistan”, in The New York Times Magazine