As one who collects socks, booties are what I wear on my feet on cold mornings. They can be worn inside slippers for added warmth and comfort, or have treads on the bottoms of them to be used as light-weight slippers for people who have diabetes (or other conditions that reduce blood circulation to the feet) to keep their feet warm. They're normally shaped like the foot, with a bend around the heal. Recently, people are starting to call them "Footies" but I don't like that name because I'd rather call an ass an ass, and a butt a butt, an ultra-low cut (but not quite no-show) sock a bootie, not to be confused with booty.
When I used to play wow, there was this city at the bottom tip of Stranglethorn Vale (STV) in the Eastern Kingdoms called "Booty Bay," and was commonly shortened to "BB," which I interpreted to "Bottom Bay," though I normally referred to that city directly as "Ass Bay" because socks are one of my passions, and I just never liked the use of the word "booty" to represent anybody's backside.
"A world that is not on the verge of annihilation can still be perfectly stimulating, and definitely not boring." - Andrea Berlinghoff
"Thanks to all my friends, I've learned that being different also makes me special. Besides, the only way to truly shine is to be yourself." - Lily Lightly