1†n. a person who advocates prohibition of the sale of intoxicating beverages.
1920  The drys cannot pretend much longer that Alberta is "prohibition".
1957  Since my last visit, Halifax has thumbed its nose at the drys, and if Angus L. Macdonald did nothing else he should be remembered with gratitude for the introduction of taverns.
2n. a type of slide or avalanche.
1958  It was the kind of slide oldtimers called a "dry" or "Whistler." The kind that often follows a fresh snowfall on crust, gathering force and volume with lightning speed, bending or snapping off stray trees like matchwood.