Spelled the same, but pronounced differently: https://www.merriam-webster.com/dictionary/chassis
If nothing else, that is a truly sadistic trivia question. I wonder if there are any other words in the English language whose plural form is spelled the same, but pronounced differently.
There are a bunch of other heteronyms, but I can't think of others that differ specifically in the plural
The Artificial General Intelligence (Claude) gives a few more examples (but only after having been prompted with your examples):
- Rendezvous, hors d'eouvre, patois, chamois, bourgeois, glacis, fracas (dialect dependent), debris (rare), pince nez (dialect dependent).
So chassis, the thing full of parts, case, same thing but without the parts?