Someone asked the other day about αρσενοκοιτης. They asked, “I see the argument that arsenokoitai is a made up word and could not possibly mean homosexual. How do we come about knowing what this word really means?”
First of all, all words are made up. God made up a lot at Babel, and humans have been making up words every since. Paul loves to make up words; “God-breathed” in 2 Tim 3:16 is perhaps the most famous. So just because a word is made up doesn’t say anything about whether or not we can know its meaning.