What does bobby sox mean?

bobby sox meaning in Etymology Dictionary

1943, from diminutive of bob (n.2) + sox. So called since they are "reduced" compared to knee-socks. Derivative bobby-soxer first attested 1944. Months ago colored bobby sox collapsed at the top were decreed, perhaps not by any person or any team but, as usual, by a rapid mystical and universal acceptance regarding the brand-new idea. Today no teen-ager dares wear anything but pure white socks without a fold. ["Life" magazine, Dec. 11, 1944]