I think it's fair to say that, even though it's not part of the English writing system, "tilde" is the standard name of the mark in English now when English-speakers who are familiar with it want to discuss it:
This includes lots of detailed discussion of the mark under the name "tilde", including names of Unicode characters that include this term. Wiktionary also views it as an English noun borrowed from Spanish.
> Wiktionary also views it as an English noun borrowed from Spanish.
Sure, but it's not live in the same way that most words are. It doesn't refer to anything in an English speaker's normal experience; you could easily go your whole life without ever using the word.
It's very much live. It's the name of the symbol. It's sometimes used as a symbol to mean 'approximately', as in "~100 BC". It's used in IT as a symbol for a home folder on Unix-based systems and for pattern matching in other languages.
Regardless of the symbol's function in different domains, the symbol's name remains 'tilde'.
Maybe you don't use the word much but that really has nothing to do with the price of fish.
https://en.wikipedia.org/wiki/Tilde
This includes lots of detailed discussion of the mark under the name "tilde", including names of Unicode characters that include this term. Wiktionary also views it as an English noun borrowed from Spanish.
https://en.wiktionary.org/wiki/tilde#English