Passover etymologies

MOSTLY SPECULATIVE: The enigmatic origins of the words of the Passover seder. The origin of the words we use during the Seder can teach a lot about the origin of the holiday. But some, including the word for 'matza', remain oddly obscure. (Elon Gilad, Haaretz. But the possibilities discussed are interesting. For example:

Let’s move on to to some of the dishes served in the Passover seder. Khazeret or hazeret is a bitter herb that Seder celebrants put on the Passover plate to represent the bitterness of the slavery in Egypt.

The word appears in the Mishnah (Pesachim 10), but is rather enigmatic. It seems to have come from the Hebrew root kh-z-r, but this root usually denotes “returning,” yet in the Mishnah, it is clearly a word related to a foodstuff.

Some other words that share the root have no obvious connection to "return" either, such as the Hebrew word for pig – khazir.

So we don’t know why khazeret is got its name, but what is it? The Talmud states that it is lettuce, and that is how it was understood by later generations too.

But Jews living in Eastern Europe had difficulty getting lettuce to eat, at Passover or any other time, and used horseradish instead. The horseradish tradition spread from Eastern Europe to other Jewish communities around the world, even those that can obtain lettuce. In fact, the practice became so commonplace that the modern Hebrew word for horseradish is khazeret.