The Scots word for a creek or small stream — on links courses, the narrow waterways that wander across fairways and play as penalty areas. Unlike the ponds of American golf, a burn sits nearly level with the surrounding turf, often walled with stone and hard to see until you are standing over it, which makes it a sneaky hazard rather than a scenic one. The Swilcan Burn crosses the 1st and 18th at St Andrews and guards the very first green; the Barry Burn at Carnoustie famously drowned Jean Van de Velde's chances at the 1999 Open.
Source: https://www.golfcompendium.com/2019/03/golf-course-burn.html · high confidence