[TeMPOraL]

> How close to "approximately no one knows about" are we in an antonym association like master/slave?

For some in the US and those adopting this particular aspect of its culture. For everyone else... well, there's some hundred other antonyms that come to mind before:

https://www.merriam-webster.com/thesaurus/master

Apprentice, amateur, loser, subordinate, subject, secondary, incompetent, inexperienced, junior - to list just a few. The only form of "master / slave" association people have - except for in the USA - is with the nomenclature used for IDE/SATA drive configuration in BIOS.

And that's in English alone. Other languages generally have their "master" equivalent disjoint from slavery or adjacent topics.