In a Word: What’s so Radical about Radishes?

A look at the etymology of both ‘radish’ and ‘radical’ will take you back to the roots of math, philosophy, and botany.

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Managing editor and logophile Andy Hollandbeck reveals the sometimes surprising roots of common English words and phrases. Remember: Etymology tells us where a word comes from, but not what it means today.

You might be surprised by how many different types of radishes are there, and the array of colors they come in. You’re probably familiar with a number of garden variety radishes in white, pink, red, and even purple, or even with the Asian daikon radish, which comes on both white and purple varieties. What you might not know about are the aptly named Spanish black radish (black skin around white flesh) or watermelon radish (green skin around dark pink flesh).

Regardless of their color, what all these radishes have in common is that the part we eat is the plant’s root — and that’s how the radish got its name. Radish comes from the Latin word radix, meaning “root.”

A photo collage of radishes: a daikon, cherry belle, watermelon radishes, and a black spanish radish.
1. Daikon, also called mooli. 2. Cherry Belle radishes, what you probably buy at the supermarket. 3. Watermelon radishes. 4. Black Spanish radishes. (Shutterstock)

But language is a fertile soil, and what began as a word for a physical root found purchase in metaphor. The root of a plant is considered its base, from which the rest of the plant grows. So when Western thinkers needed a word for a basis of thought or government, they reached for the Latin adjective radicalis, “of or having roots.” By the 14th century, this had become radical in English, and it was a synonym for fundamental.

Mathematics flourished, too. In the 16th century, mathematicians began talking of the roots of numbers — square roots, cubed roots, and so on — and when they created a mathematical symbol for it, they used the same vocabulary and called it the radical sign (√).

So in philosophy, science, and math, the word radical for a long time pointed back to a root of some sort. But then things changed. At the tail end of the 18th century, an extreme section of the British Liberal Party was calling for fundamental changes in their party’s stance. They called for radical reform — radical because they wanted to reform the party’s ideological roots — and very quickly these reformers became known as radicals.

By the end of the first decade of the 19th century, radical had come to mean not the metaphorical root but a large change or shift from that root — a complete flip from its earlier meaning. The concept of “radical beliefs,” then, means exactly the opposite today as it did 250 years ago.

The word radical continued to grow and change, from the notion of “unconventional” in the 1920s to 1970s surfer slang to general 1980s youth slang, so that today, radical has gone far from its root in root.

But a radish is still a radish.

Featured image: Shutterstock

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