Here’s another great untranslatable word: Ilunga
As well as being a common family name in Democratic Republic of the Congo, ilunga (from the Southwest Congo language Tshiluba) is famous for being the world’s most difficult word to translate. The closest most professional translators can get is a person who is ready to forgive and forget any first abuse, tolerate it the second time, but never forgive nor tolerate on the third offense.