When the word tariff entered English in the 1590s, it referred to an official list of customs on trade, or even a mathematical table of any kind. This makes sense; in that medley of Medieval Latin and Italian, tariffa or tarifa meant a "list of prices", something not that dissimilar. The Italians, who traded a lot with Muslims, stole both the idea and word from them, leading us to Arabic ta'rif, which most recently meant "inventory", but before that meant "information" and before that meant "notification". This is all the more important meaning because it is best connected to the previous word's definition: Arabic arafa meant "he taught". This is probably from a Semitic root like r-f (no vowels, of course), which in turn could be said to be Afro-Asiatic. R-f generally had something to do with knowledge. Usage of the word tariff has decreased a lot since the early 1900s, but searches for the word in Google has dramatically increased in the past few weeks, with all the political drama.
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.