What is a mensch? I have heard the term, but do not understand what it is supposed to mean.
Mensch (Yiddish מענטש; also mentsch, mentsh, mensh, or mench, plural: mentschen, German plural: Menschen) is a German noun meaning a "human".
In Yiddish (from which the word has migrated into American English), mensch roughly means "a good person." A role model. A "mensch" is a particularly good person, like "a stand-up guy," a person with the qualities one would hope for in a dear friend or trusted colleague. According to author and Yiddish popularist Leo Rosten,
[A] mensch is a 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. (Rosten, Leo. 1968. The Joys of Yiddish. New York: Pocket Books. 237)