How do you use the Lemmy search but exclude words containing the term (i.e. look for "sword" but not "password")?

I'm trying to set up a periodic crawl for terms of interest to see if communities pop up that discuss them. Some are easy, like "Mordhau" because no other words contain it. On the other hand, "sword" and "HEMA" are problematic because things like "password" and "mathematical" contain them.

I tried to put quotes around the string but that returns nothing, and padding a space on either side didn't change results.