I'm looking for a word. It's when you put a sword in something that's attached to your waist. I don't know how to spell it. The closest I've gotten was seath.

The word you might be looking for is "sheath." A sheath is a protective covering for a sword or knife that is attached to a person's waist or belt.

Thank you

You're welcome! If you have any more questions or need help with anything else, feel free to ask.