In programming languages, they have a concept called "reserved words". When you program, the programming language (any one of them!) allows you to name your own variables, constants, class names and function names. You are allowed to go for it! However there is a caveat, you are not allowed to use the programming language's reserved words. These words are solely for the use of the programming language because its semantics is locked in. You are not allowed to use these reserved words for your naming of variables, constants, class names and function names.
For example, in Java, if you say this...
Java will trap you and won't move further in its analysis of your code (hence, we say it won't compile). The reason is that you have used the reserved word return to name your integer variable. That word is reserved for Java. You did something illegal.
I think the Bible does the same. Right now I can identify a couple of words that are "reserved words" by Scripture. One of them is "justification" and the other is "predestination".
The Bible exclusively uses these words in reference to believers in the Gospel of Christ only. It does not use it any other way.
If you can identify some more, let me know.