A friend of mine recently asked me why people with non-medical degrees are called doctors, and that led me down an interesting rabbit hole. The term, which has been around since 1387, originally meant "expert" in general, and the connotation of "medical expert" only began to be common in the sixteenth century. As Old French doctour, it meant "teacher", especially in reference to religious teachers, and that traces to Latin doctor, also "teacher". The root of that is the verb docere, meaning "to teach". Finally, that derives from the Proto-Italic reconstruction dokeo, from Proto-Indo-European dek, "to take". The verb to doctor meaning "falsify" emerged in 1774 on the notion of repairing something like a doctor, and usage of the word doctor in literature has been steadily increasing over time.
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.