ystävistään
ystävistään is a Finnish word that translates to "about their friends" or "of their friends". It is the partitive plural of the word ystävä, which means "friend". The suffix "-stä" indicates the partitive case, often used to denote something that is a part of a whole or something that is being discussed or thought about. Therefore, ystävistään refers to friends in a context where they are being described, mentioned, or are the subject of a sentence.
For example, in Finnish, one might say "Hän puhui ystävistään" which means "He/She talked about their friends".