Mensch (Yiddish: מענטש mentsh, cognate with German: Mensch "human being") means "a person of integrity and honor." The opposite of a "mensch" is an "unmensch" (meaning: an utterly unlikeable or unfriendly person). According to Leo Rosten, the Yiddish maven and author of The Joys of Yiddish, "mensch" is "someone to admire and emulate, someone of noble character. The key to being 'a real mensch' is nothing less than character, rectitude, dignity, a sense of what is right, responsible, decorous." The term is used as a high compliment, expressing the rarity and value of that individual's qualities.
It is used in Hungarian --- we are using German/Jewish words --- (not a compliment, especially not a high one --- by the way):