Stable just means it's pegged to fiat 1:1 disregarding the value of the fiat itself.
There's also stablecoin that is pegged to gold. So, really the word just means digitalized fiat nothing more nothing less in the case of fiat pegged stablecoin.
Great points raised here. The term “stablecoin” definitely creates the illusion of security, but as mentioned, it's only stable relative to its fiat peg. Which itself is constantly eroding in value due to inflation. It might be more accurate to call them “fiat mirrors” or “digitized fiat wrappers.” That said, they still serve a practical purpose in crypto markets by reducing volatility in the short term, even if they’re not a true store of value in the long run.