The Unicode character U+029A ʚ is named LATIN SMALL LETTER CLOSED OPEN E.

Both CLOSED and OPEN? That’s a neat trick.

More seriously, I can see why it’s called that — it’s similar to U+025B ɛ LATIN SMALL LETTER OPEN E, except that the open part of the glyph has been closed up. But it still seems fairly odd.

Also of interest is U+025E ɞ LATIN SMALL LETTER CLOSED REVERSED OPEN E, in that the order of the applicable adjectives is CLOSED REVERSED OPEN. Given that this is a reversed version of a CLOSED OPEN E, you might expect it to be a REVERSED CLOSED OPEN E instead. But it seems to be analysed as a closed version of U+025C ɜ LATIN SMALL LETTER REVERSED OPEN E. If forced to, I’d probably guess that ɜ has been around longer than ɞ.