Colon

In English, the word colon is used both to denote the punctuation mark : and to refer to the large intestine.

It may seem, what could possibly be in common between these two words? Actually, nothing. Both emerged from Ancient Greek, and the latter meaning is straightforward: κόλον is a clear designation for the large intestine.

There's also the word κῶλον, which is pronounced similarly, but refers to a part of the body (arm, leg) or a part of a sentence. The interesting part is that in Ancient Greek, the symbol : was an analogue of our period and marked the end of a phrase. And this very phrase was called κῶλον.

Much later in English, the colon turned into a variety of the comma, but the name hasn't changed, leaving room for puns.

For instance, some unfortunate people who had a piece of their intestine removed due to cancer, Crohn's disease or other problems, joke about now having a semicolon ;, that is, a half-intestine (Google "semicolon cancer").

When was the last time you had a colonoscopy?