Military kids (from God knows where) called 'em zorries. Haven't heard that term since.
They were probably stationed in Japan!
Zori is the Japanese for the sandal.
(At least that is what my Japanese neighbor and friend told me when we lived next door to each other in Hawaii.)
Sometimes people call them Tabis but tabi are the fabric, ankle-height "socks" with big toe covering separate from the other toes. That's so the thong of the zori slips in. When you remove the Zori upon entering a house, your feet are still covered by tabi.
In Japan tabi can be plain black or white or any other fabric. Some QUITE expensive.
wow