Doctor

The English word "doctor" traces its roots to the Latin verb docēre, which means "to show" or "to teach". In the Middle Ages, the title was originally used to designate highly learned scholars approved to teach at universities, rather than someone who provided medical treatment.

The term combines the verb root doc- (to teach) with the agent suffix -tor (meaning "one who does"). This structural breakdown makes it the literal Latin equivalent of the English word "teacher". Historically, the word evolved into an agent noun from Medieval Latin, defined broadly as "religious teacher, adviser, scholar" before shifting to its broader modern uses in healthcare and academia.

Whom should we really call a doctor?
https://pmc.ncbi.nlm.nih.gov/articles/PMC5973890/