Where to look up the age of words

When I’m writing fiction with a historical bent, sometimes a word strikes me as “modern,” and I wonder if a character from a certain time period would know it. I find the Online Etymology Dictionary to be absolutely invaluable!

Did you know that the verb “buzz” dates to the late 15th century? Yet the word “beep” dates to the late 1920s, used as an imiation of the sound a car horn makes!

Isn’t the world interesting?