hamentaschen

The etymology of hamentaschen is fairly well known. They did not originally refer to Haman (and therefore the Hebrew אוזני המן oznei haman - came much later.) These pastries were originally called "mahn-taschen". Mohn means "poppy" in German, and tasch is a pocket. When you add the Hebrew definitive article ha, they become ha-mahn-taschen, which is easy to associate with Haman. Of course there are many "midrashim" (really Purim torah), that expound on the connection: that Haman had three-cornered ears like the pastry, or had a three cornered hat, or a new one for me, that it refers to המן תש - "Haman became weak."

But here at Balashon, we go deeper. What is the origin of tasch and mohn?

From here we see that tasch from comes from Middle High German tasche, and earlier from Old High German tasca. Tasca is related to the English word "task", and both are related to "tax". What's the connection between task, tax and pocket? The Online Etymology Dictionary explains as follows: "amount of work imposed by some authority," to "payment for that work," to "wages," to "pocket into which money is put," to "any pocket." (A connection between Haman and taxes can be seen in the more recent custom to boo at the reading of the word mas מס - tax in the Megila, the same way as Haman is booed.)

Mohn in German is related to the Dutch maan, and has a number of related words in Indo-European languages, including the Greek mekon.