the.com/radical

means Favoring extreme, fundamental change rather than gradual reform — or, loosely, anything impressively thorough or intense.

from From Latin 'radix,' meaning root — the same root (pun intended) that gives us 'radish.' To be radical originally meant getting at the root of a thing, not just its branches; mathematicians still use 'radical' for root signs. The political sense arose because reformers who wanted to fix problems at the root called themselves radicals, and the word gradually drifted from 'fundamental' to 'extreme' to, eventually, 1980s slang for 'awesome' — a long way from a vegetable's roots.