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Few people ever wonder why their elbows are called elbows, but there is a reason.
The word breaks into two parts el and bow.
Inside your forearm are two bones called the radius and the ulna. The ulna is named from Latin and Latin in turn took the name ultimately from an Indo-European root el meaning “forearm.”
There are obsolete units of measure that came about due to the convenience of measuring off things against parts of the body. A foot is the obvious example that is still in use but the forearm was just as handy for measurement purposes and that’s why you sometimes hear about ancient things having dimensions in ells or cubits.
Cubitum was also used in Latin to describe the elbow or the distance from the elbow to the finger-tips.
So el means “arm” or “forearm.”
Bow is still a very recognizable word meaning “bend”; we bend a bow to shoot arrows and when we finish a performance we bend at the waist and take a bow.
Thus the literal meaning of the word elbow is “arm bend.”
In common parlance though, when someone mentions the elbow they usually mean the pointy bit; the outside of the arm bend.
Is there a name for the inside of the arm bend; the crease inside your elbow?
I haven’t come across a common name for this feature of the body but since physicians have a label for nearly every part of the body there is a technical name and that’s cubital fossa.
Cubital is recognizable as meaning “elbow” from the Latin cubitum.
A fossa is a shallow depression from the Latin word for “ditch” so that cubital fossa literally means “elbow crease.”
Five days a week Charles Hodgson produces Podictionary – the podcast for word lovers, Thursday episodes here at OUPblog. He’s also the author of several books including his latest History of Wine Words – An Intoxicating Dictionary of Etymology from the Vineyard, Glass, and Bottle.
the inside of your elbow is called chelidon