1. A decorative pair of ceramic birds mounted on a rotating platform.
2. Unsightly pendulous sagging breasts often due to the combination of gravity and aging.
"You'll never believe what I picked up from the garage sale. Look, swivel tits!"
"Don't go in there! There is an old lady prancing around naked in the locker room. I just saw her swivel tits, and now I am scarred for life..."