There have been a lot of different spellings of the word store throughout history. Early forms included stoore, stor, stoer, istor, and story, and right up until the turn of the seventeenth century, there were still people spelling it as stoar. The first attestation we have in English is from a 1264 collection of political songs, where it was used as a verb (the noun came three decades later). The word was borrowed from the Anglo-Normans after they invaded and traces to Old French estorer, which meant "to construct". Estorer is from the Latin verb instaurare, meaning "establish" or "renew". That's composed of the prefix in- ("in", from Proto-Indo-European en), and the root staurare, which derives from PIE steh, "to stand up"). Related: I now have a store where I'm selling infographic prints! Go check it out!
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.