maven

The story

1. Hebrew · derived fromמֵבִין“one who understands, connoisseur, expert”
2. Yiddish · borrowed fromמבֿין“connoisseur, expert, know-it-all”
3. English todaymaven

From Yiddish מבֿין (meyvn, “connoisseur, expert, know-it-all”), from Hebrew מֵבִין (mevín, “one who understands, connoisseur, expert”), from הֵבִין (hevín, “to understand”). The word is said to have been popularized by its use in an advertising campaign for Vita Herring launched in the United States in 1964, which had a character called the “beloved [herring] maven” promoting the product.