For example, if using the term “minor”, one needs to understand that the halachic term “ketanah” or “katan” is not precisely defined as “minor”, because the parameters are different.
I don’t agree with that either, even though “minor” is a legal word and has no meaning outside a legal context.
When you use the term “minor”, it is associated with its particular context. The same as any other word.
If I tell you that I was in Canada last week, and tried to buy beer and had to prove to the guy that I wasn’t a minor, would you jump all over me and say “but you’re 20 years old, so you really are a minor!”? No, because in Canada they sell beer to 20 year olds and they aren’t minors.
If I tell you that I was in Florida last week and I murdered someone by turning on a counterfeiting machine which I didn’t realize was hooked up to an ebola vial and set it loose; would you say “but there is no felony murder rule in <insert your state>!” No, because in Florida murder has different rules. So if I translate retzicha as murder, that works because it means “murder,” and has the rules of the context it is used in.
Ketana means “minor” in the legal sense. And every legal system decides what age they want to treat as a minor. It doesn’t mean the legal system that you happen to want to “shtuch” me with.
But rape is different, because it has a common meaning outside of the legal system. When people say the word “rape” they aren’t referring to any legal context. Rape is similar to words like “rob” and “steal” which have a common meaning outside of any specialized legal meaning.