Welllllll.... I guess those are very literal interpretations of the names. Very good work finding those.
Hmmm, "Usb flash drive" appears to be the most "correct" one,
but there are of course exceptions, I guess these:
can be called differently with no risk of misunderstandings.
I've heard that before, but I still think USB drive isn't specific enough; as I stated earlier, there are many kinds of USB Drives. None the less, if someone just blurted out "where's my USB drive," I would think flash drive, not a hard drive with a USB connector or something like that.
Here, we call it USB Drive (short for USB Flash Drive).
It appears that so far, (USB) Flash Drive has won.