heyhey! curiosity question for fedi linguists ​:renote_requested:​

what word(s) sound the most similar across the most european languages? ie if said by any given language in the set, a speaker in any other given language in the set is likely to understand it, regardless of if they've ever even heard anything else in the language it's said in or not. meaning should be
approximately the same
and, historically, why these over others? any reason these are closer than most?

speculation and imperfect answers welcome! :3