Usually, so far, the alternate meanings seem somewhat related (ie 月 for moon/month) but I don’t see the etymological connection of “replacement” and “era.” The closest I can come up with is that one like, kingdom’s reign comes and replaces the other but seems like a long stretch…is there another link that’s more obvious? Is it two ideas that were using different glyphs a thousand years ago that just happened to merge into one? Am I missing something that’s right there??? thanks
Ahh, thanks Leebo! I had a hunch i was on the right track with the like, kingdoms and reigns angle…it’s a couple layers of abstraction away but I can see it for sure.
It is possible for completely unrelated concepts to get introduced, usually from sound borrowing. It’s why 北, which we mainly think of as “north”, is used in the word 敗北 “defeat.” Because 北 was originally two people facing away from each other > abstracted to moving away > abstracted to defeat.
Then someone started using it for “north” because they sounded the same in ancient Chinese. And boom… it almost exclusively gets used as north now.
But that didn’t happen with 代 as far as I can tell.
Oh, right, I forgot about how common sound borrowing actually is – I knew of it happening with characters being taken from Chinese because they have the sound a Japanese term uses but wasn’t related by glyph…I guess I just assumed that was a one-time-per-kanji kind of thing. I didn’t know that there could be other, multiple meanings attached to a single kanji using sound readings like that!
I can’t believe how helpful this community is and how i got my very specific question answered IMMEDIATELY. Thanks so much!!!