Treif (also written trayf, treyf or traif) is the Yiddish word that means “unkosher.” It is an adaptation of the Hebrew word treifah, which describes something that has been mangled or torn asunder. Here’s how this word came to mean “unkosher.”

Treif in the Torah

In the Bible we read that an animal that has been mauled (treifah) is forbidden to be eaten, as all kosher meat and poultry must be killed by way of shechitah, kosher slaughter. As the verse says, “Flesh torn (treifah) in the field you shall not eat; you shall throw it to the dog[s].”1

The meat of animals that die of other causes, natural or otherwise, is also forbidden, as we read, “He shall not eat a carcass or anything that was torn (treifah).”2 Thus, the word treifah expanded to include all forbidden dead things.

The treifah net extends even wider. Through carefully analyzing the verses, the sages understand that the flesh of an animal that has not died of its wounds, but is injured or unhealthy to the degree that it would die soon, is forbidden, even if someone performed shechitah on it before it dies. Such an animal is also included under the rubric of treifah.

The Colloquial “Treif”

In common parlance, anything that is not kosher is also called treif. So a mixture of milk and meat can be called treif, as is the flesh of a non-kosher species.

Then, moving beyond the confines of food, any action can be informally referred to as treif. This mirrors the use of the word “kosher,” which literally means “fit,” to refer more broadly to anything that is aboveboard or legit.

American Treif

Among some pious European Jews, America was known as di treifine medineh, “the treif land,” because of the assumption that those who moved there would soon abandon traditional Jewish practices. All this was turned on its head one winter day in 1940 when the previous Lubavitcher Rebbe, Rabbi Yosef Yitzchak Schneersohn, arrived in New York Harbor, having been saved from Nazi-occupied Poland. “America is nisht andersh,” he declared, “America is no different.” He then set about founding a string of Jewish institutions all across the American Northeast and Canada, which eventually gave rise to the thousands of Chabad centers all around the world and the Jewish renaissance they have created.