also bobby socks, 1943, from diminutive of bob (n.2) + sox. So called because they are "shortened" compared to knee-socks. Derivative bobby-soxer "adolescent girl," especially with reference to fans of popular crooners, first attested 1944.

Months ago colored bobby sox folded at the top were decreed, not by anyone or any group but, as usual, by a sudden mysterious and universal acceptance of the new idea. Now no teen-ager dares wear anything but pure white socks without a fold. [Life magazine, Dec. 11, 1944]

masc. proper name, from an Old North French form of Old High German Hrodberht "bright-fame, bright with glory," from hrod- "fame, glory" (from Proto-Germanic *hrothi-), + *berht "bright" (from PIE root *bhereg- "to shine; bright, white"). Never a king's name, though it was the name of William the Conqueror's rebellious oldest son. "It was introduced by Normans during the reign of Edward the Confessor and became very popular" ["Dictionary of English Surnames"].

In Middle English, from mid-13c., also "a designation for a robber, vagabond, or lowly person" ["Middle English Compendium"]; hence Robertes men "robbers, marauders;" Robert-renne-aboute "a wastrel, a good-for-nothing."

"conoid-shaped metal weight attached to the end of a plumb-line," 1835, from plumb (n.) + bob (n.1).