The word catalog developed from its other spelling catalogue in the late nineteenth century as part of a movement to create more American-looking words. In Old French, the word looked the same and meant "index", and that came in the fourteenth century from Latin catalogus, which traces to Greek katalogos, "enrollment" or "register". Katalogos comes from the the fairly common prefix kata-, meaning "down" (also present in words like catastrophe and cataract), and the root legein, meaning "to say" or "count" (we've seen this before in the suffix -ology). Finally, kata comes from the Proto-Indo-European reconstruction kmt, also "down", and legein is from Proto-Indo-European leg, meaning "gather or collect". So, together, a catalog gathers down all the information from a store.
Hello! I'm Adam Aleksic, a senior studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy trivia, politics, vexillology, geography, board games, conlanging, art history, and law.