Alternative form of southwesterthe wind; this is the usual spelling for the hat
1913, Joseph C. Lincoln, Mr. Pratt's Patients Chapter 1, For a spell we done pretty well. Then there came a reg'lar terror of a sou'wester same as you don't get one summer in a thousand, and blowed the shanty flat and ripped about half of the weir poles out of the sand.
a waterproofhat with a long brim at the back, covering the neck.
1938, Xavier Herbert, , New York: D. Appleton-Century, 1943, Chapter X, p. 165, https://archive.org/details/capricornianovel00herbJoe Crowe was perched in the driving-seat, clad in oil-skins and sou'-wester, crouched in the rain, clutching two iron buckets.
