In article e13fc8b3-c956-4c09-b7c3-
,
says...

I'm willing to slide on the last one, as the US and Brits have split
on carcass/carcase, but the first two - no way. Especially the first
- no final Xs unless it's a royalty lineage designation.

Just variant spellings of the same word. Carcass equals carcase (OED).
There are no further distictions to be made.

It derives from the word charcois.

....and it all adds up to a frame of bones or wood on which something is
hung or was hung.