|(US) history a number of repressive puritanical laws of the colonial period, forbidding any secular activity on Sundays|
Laws that prohibit certain businesses from opening on Sunday or from selling certain items on that day. Blue laws often apply to bars and to alcohol sales. Originally enacted to allow observation of Sunday as a Sabbath, blue laws have come under attack as violating the separation of church and state. The courts, however, have upheld most blue laws, on the basis that their observance has become secular and promotes Sunday as a day of rest and relaxation.