Origin: Latin suffix -al
Radical has 13 different meanings across 2 categories:
(chemistry) two or more atoms bound together as a single unit and forming part of a molecule
"The hydroxyl radical in the atmosphere reacts quickly with other molecules to break down pollutants."
an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule that has lost an electron and will stabilize itself by stealing an electron from a nearby molecule
"in the body free radicals are high-energy particles that ricochet wildly and damage cells"
a person who has radical ideas or opinions
"The school invited several political radicals to speak about their vision for reform."
(mathematics) a quantity expressed as the root of another quantity
"The radical symbol indicates that we are looking for the square root of the number beneath it."
a character conveying the lexical meaning of a logogram
"The scholar spent hours tracing the radical in ancient Chinese characters to understand their original pictorial roots."
A member of the most progressive wing of the Liberal Party; someone favouring social reform (but generally stopping short of socialism).
"The radical MP proposed sweeping land reforms while rejecting outright nationalization."
In plain English: A radical is someone who wants to make big, sudden changes to how things are done.
"The radical suggested that we should overthrow the government immediately."
markedly new or introducing radical change
"a revolutionary discovery"
"radical political views"
Favoring fundamental change, or change at the root cause of a matter.
"The radical reformer argued that true justice could only be achieved by dismantling the entire existing legal system rather than making minor adjustments to it."
In plain English: Radical means extremely new, unconventional, and far different from what is normal or expected.
"The radical change to our daily routine shocked everyone at first."
Usage: Use "radical" to describe changes that address the core causes of an issue rather than just surface symptoms. This adjective often contrasts with moderate approaches by emphasizing deep, transformative reform instead of incremental adjustments.
The word "radical" comes from the Latin term meaning "pertaining to a root." It entered English through Middle English while retaining its original sense of being rooted in something fundamental.