ratz = edge (border) (noun) (some things Google found for "ratz": a common term; a last name; a 2000 TV movie for teens; The Pear Ratz are a country rock band; a former political party in Israel; a 2003 French language animated TV series about two rats; Surf Ratz is a shop in Florida)
Word derivation for "edge (border)" :
Basque = ertz, Finnish = reuna
Miresua = ratz
This is one of those Miresua words you wouldn't find in either Basque or Finnish. Words don't start with R in Basque. Words don't use the letter Z in Finnish.
I use the vowel A, instead of the common E, because this word is part of the compound word for beach, see the previous post.