Why is the name Dick short for Richard? This video—from the YouTube channel Today I Found Out—explains that it wasn’t a direct link, but rather the result of a chain of nicknames. Dick was chosen simply by rhyming names and nicknames that were popular at the time, and it rhymed with Rick—another nickname for Richard we still use today.
We might never be able to shake the word’s association with male anatomy. But it was used as a nickname for Richard long before it became slang for that. So it was a little less awkward at the time.
Today I Found Out has many more historical nuggets like this when you subscribe to its channel.