blue law

plural blue laws

1. CanadaUShistoricalA restrictive religious-based law in colonial New England, especially preventing leisure activities on a Sunday.First known use 18th c.

   Years ago, because of the Blue Laws, we couldn't serve drinks on Sunday over the bar, so we set up tables in the aisles. And we'd have different acts on a stage up front.

   1976 February 7, Rose Flower, quoting Jimmy McGrath, “Playland: The Friendliest Place In Town”, in Gay Community News, volume 3, number 32, page 13

2. CanadaUSbroadlyAny puritanical or restrictive law, especially one that prohibits or restricts commercial activity on a Sunday.First known use 19th c.

   [I]t's actually a way around the Swiss blue laws demanding that shops close from Saturday afternoon until Monday morning. The laws apply everywhere but the airport, so they built a massive supermarket in the Swiss Air terminal.

   2001, David Sedaris, diary entry January 22, in Theft by Finding, Back Bay Books 2017, p. 441