The term catalog evolved from its alternate spelling catalogue in the late 19th century as part of a movement to create more Americanized words. In Old French, the word had a similar appearance and meant “index”, and it was borrowed in the 14th century from Latin catalogus, which has its origins in Greek katalogos, meaning “enrollment” or “register”. Katalogos is derived from the prefix kata-, meaning “down” (also found in words like catastrophe and cataract), and the root legein, meaning “to say” or “count” (as seen in the suffix -ology). Furthermore, kata is traced back to the Proto-Indo-European reconstruction kmt, also signifying “down”, while legein is from Proto-Indo-European leg, meaning “gather or collect”. Therefore, a catalog essentially gathers all the information from a store.
