Words have meanings, and those meanings are cataloged in a book called a "dictionary"
If you just make up meanings that suit what you WANT the words to mean, then we are suddenly not speaking the same language. If I say red, and you decide that means green - we are no longer communicating.
Words matter, definitions matter - they are absolutely necessary to effective communication. This is why people who can't escape the traps of using slang are not able to get good jobs - nobody can communicate with them effectively.
If you're going to use a word, know what it means. If you're going to misuse a word, expect someone to question you about it.