Why is the ninth month called September?
Old English snod "ribbon for the hair," from Proto-Germanic *snodo (cf. Swedish snod "string, cord"), from PIE root *(s)ne- "to spin, sew" (cf. Lettish snate "a linen cover," Old Irish snathe "thread;" see needle (n.)). In the Middle Ages, typically worn by young unmarried girls, hence "It was held to be emblematic of maidenhood or virginity" [Century Dictionary]. Modern fashion meaning "bag-like hair net" first recorded 1938 (these also were worn by girls in the Middle Ages, but they are not snoods properly).
either of two types of hair ornament worn by women. The Scottish snood was a narrow circlet or ribbon fastened around the head and worn primarily by unmarried women, as a sign of chastity. During the Victorian era, hairnets worn for decoration were called snoods, and this term came to mean a netlike hat or part of a hat that caught the hair in the back. In the 1930s the name was given to a netlike bag worn at the back of a woman's head to hold the hair. During World War II snoods were immensely popular in factories, where they were worn to keep hair from being caught in machinery.