[esrauch]

I think you are confused by terminology here and not by behavior, "immutable variable" is a normal terminology in all languages and could be says to be distinct from constants.

In Rust if you define with "let x = 1;" it's an immutable variable, and same with Kotlin "val x = 1;"

[psychoslave]

Lore and custom made "immutable variable" some kind of frequent idiomatic parlance, but it’s still an oxymoron in their general accepted isolated meanings.

Neither "let" nor "val[ue]" implies constancy or vacillation in themselves without further context.

[esrauch]

Words only have the meaning we give them, and "variable" already has this meaning from mathematics in the sense of x+1=2, x is a variable.

Euler used this terminology, it's not new fangled corruption or anything. I'm not sure it makes too much sense to argue they new languages should use a different terminology than this based on a colloquial/nontechnical interpretation of the word.