Lox

Lox is a fillet of brined salmon, which may be smoked. Lox is frequently served on a bagel with cream cheese, and often garnished with tomato, onion, cucumber, and capers. The American English word lox is a borrowing of Yiddish laks , itself derived from Middle High German lahs (modern German form: Lachs) stemming from Proto-Germanic *lahsaz and ultimately Proto-Indo-European (PIE) *laks. Lax, chiefly a British English word for salmon, is a doublet of the word inherited from Middle English. The word has various cognates in various Indo-European languages. For example, cured salmon in Scandinavian countries is known by different versions of the name gravlax or gravad laks, with lax meaning salmon. The word is so remarkably widespread and stable across IE languages that it probably existed in its current form in a PIE language. The traditional belly lox is known as such because it is made from the fatty fish belly. The cut is described as "paper-thin". Traditionally, the product is unsmoked and preserved by dry curing, leading to a very salty taste. As a result of consumer preferences, mass-produced "lox" generally use less salt and add cold smoke, making them more similar to a "Nova" (see below). A different cut may be used, too, in these versions.

Source: Wikipedia