Frum (Yiddish: פֿרום‎, lit. religious, pious) is a word that describes Jewish religious devotion. The appellation is generally, but not only, applied to certain movements within Ashkenazic Orthodox Judaism, and used by some members of these groups as a self-reference.Frum (Yiddish: פֿרום‎, lit. religious, pious) is a word that describes Jewish religious devotion. The appellation is generally, but not only, applied to certain movements within Ashkenazic Orthodox Judaism