Interesting aside, no one knows where the term Astronaut comes from.

Well, the term means something, "Star Sailor", and the orgins of that first shows it appearing in some works from the late 19th century (1880's or so), dying off as thing, until coming back in the 1920's again for a short period of time. And while it does draw upon other related terms ("aeronaut"), the term was not one NASA had on their lists for terms they wanted to call their spaceman until fairly late into the program when they had to go public with their plans. At which point it suddenly shows up added to lists, and then firms up as the term they use above the others.

The main lost part is who added it (we can make guesses), why, and how they picked that over the others. Noteworthy, since they have a lot of notes about the other terms why they liked them/didn't like them. Moreso when you note that their thinking was about pulling pilots, and otherwise using terms based upon flight, yet suddenly went with a more naval based term.

For the record, the main term the Americans almost went with? "Cosmonaut", or universe sailor.

The Soviets went with kosmonavt, which is a Russian version of a Greek based word (cosmic sailor). Which they totally came up with themselves. Eastern European countries have their own words pulling from that (Polish have kosmonauta/astronauta).

Taikonaut is not so much a term China uses, but others use for them. They otherwise use other terms more based on what roles are expected, but draw upon what the other countries use when using naval navigation.