Radical Meaning: Every Sense Grows From the Root

Radical meaning, sense by sense

1. Fundamental or thorough: affecting the basic nature of something. "The company made radical cuts" means the cuts went deep.
2. In politics: wanting complete or sweeping change to social or political systems, rather than gradual reform. As a noun, a radical is a person with such views.
3. In maths: to do with a root of a number. The radical sign √ shows a square root, and an expression like √5 is called a radical.
4. In chemistry: a group of atoms that acts as a unit. A free radical is an atom or molecule with an unpaired electron, which makes it very reactive.
5. In medicine: treatment meant to remove the whole cause of a disease, such as radical surgery.
6. As slang: excellent or impressive, mainly in American youth speech of the 1980s; now often shortened to rad.

Examples of radical in sentences

• Moving from paper files to a shared online system was a radical shift for the small clinic.
• The architect's radical design turned the old warehouse into a light filled library.
• Simplify the radical √50 to 5√2 before you add the terms.
• Some foods are described as rich in antioxidants, which react with free radicals in the body.
• "That skateboard trick was radical," her uncle said, sounding very much like a teenager from another decade.

The political sense, explained neutrally

In political talk, radical describes ideas or people that want deep, structural change rather than small adjustments. It is a relative word: what counts as radical depends on what is normal in a given place and time. A view can be called radical in one country and ordinary in another.

Historically, the term has been used across the political spectrum, for movements that wanted to extend voting rights, end slavery, redistribute land, shrink the state, restore older traditions or overturn a monarchy. Some people wear the label with pride, as a sign of boldness. Others use it as a warning, to suggest that an idea goes too far. Because of this, the same policy may be called radical by its critics and simply necessary by its supporters, and readers do well to ask who is using the word and why. Related terms such as liberal, conservative and status quo are covered on their own pages.

Radicalize, radicalism and other forms

Radically means in a thorough or extreme way: "The town has changed radically." Radicalism is the holding of radical views. To radicalize (radicalise in British spelling) is to cause someone to adopt more extreme views; in news reports radicalization often refers to people being drawn toward violent extremism, though the word itself only means becoming more radical.

Useful pairings: radical change, radical idea, radical overhaul, radical rethink, a radical departure from, radical reform.

From roots in the soil to roots of numbers

Radical first shows up in Middle English records toward the close of the 1300s, taken from Late Latin radicalis, having roots, from radix, root, which also gave us radish. At first it meant rooted or vital to life. By the 1650s it meant going to the origin, or essential. The maths sense of a root sign is recorded from the 1680s. In politics, radical reform was in use from 1786, and the noun for a person seeking sweeping change from about 1802. The chemistry sense dates from the early 1800s, and the American slang sense from the early 1980s, growing out of 1970s surfer talk.

Radical versus extreme, drastic and progressive

A radical change need not be sudden or harsh, which is where it differs from drastic. A gradual plan can still be radical if it rebuilds the basics. Words about government, rights and public debate are grouped on our law and society page.