A podiatrist limits his or her practice to conditions that affect the feet.
Have you ever received a birthday or holiday card that arrived the day after the event? Sometimes the post office just isn't able to deliver fast enough for us. This may be unfair to the postal system, but I always think of this when I see the word post, which means "after." Postoperative for example means "after surgery." Most doctors consider postmortem patients to be beyond help. (Dr. Frankenstein was a notable exception.) Postmortem, you see, means "after death."
Speaking of doctors, the word doctor comes from the Latin. Guess what it means: