It depends on a couple of factors. Personally I always write subtraction as "x - y", so I never have any issues. Also, if undeclared variables are a compile-time error, the compiler will (probably) complain loudly about "x-y". So you can fix that quickly and easily, it's not too bad.
The one error that might be problematic depending on the language's semantics is if you write something like "x.y-z" intending to subtract "z" from "x.y", but in fact you are going to get the "y-z" property of "x". I must say that in Earl Grey you'll unfortunately end up with "undefined" as the result of that expression (saner languages would raise an exception on a missing property). I have never had that issue in practice, but then again, I always space subtraction.
I don't have a problem with "x - y" and approve of hyphenated names if you can't support spaces within names.
I had initially jumped to the conclusion that your language would use a postfix notation and be more influenced by Forth than LISP. This is because I assumed it's name alluded to the way that Captain Jean Luc Picard would program his replicator.
The one error that might be problematic depending on the language's semantics is if you write something like "x.y-z" intending to subtract "z" from "x.y", but in fact you are going to get the "y-z" property of "x". I must say that in Earl Grey you'll unfortunately end up with "undefined" as the result of that expression (saner languages would raise an exception on a missing property). I have never had that issue in practice, but then again, I always space subtraction.