It can be amusing at times when people mis-speak (hopefully it just mis-speaking) and you know what was intended to be said. I was told a story a few days ago about a young fellow who was concerned about a roommate doing things in their apartment. The details are not important, but the term "contraseptic" (as a noun) was used in the original telling without any sense of irony or in-joke.
I know what contraceptives are. And that they can be called prophylactics. And what contraception is. But I had not heard of a "contraseptic" before. Then, there likely a good many things I have not yet heard of. So I went to a search engine or two and looked around the web. Nope, no stunning revelation of something I've managed to miss for some time. Just a lot of advice to people using that word, which can all be summed up in two words: don't mate.
Ah, but 'contraseptic' does have that odd appeal of something that feels like it ought to be a word. But it lacks a proper definition. Perhaps you can add to the lexicon: How would you define "contraseptic"?