Huge baggy socks that droop over the wearer's calves. They are so loose, in fact, that keeping them up requires a special kind of
glue only sold at loose socks shops. Loose socks are a famous piece of
Japanese schoolgirl fashion, following closely on the heels of tiny
cellular phones and
sticker machines. In Japanese, they are called
rûsu sokkusu... just say "loose socks" with a really bad Japanese accent, and you should be able to approximate the pronunciation.
Why loose socks are popular remains a mystery, but in America they have become something of a fetish item, and sell for ridiculous prices on the internet.