root radical radial radiate eradicate

radical ['rædikəl]
of or from the root or base; fundamental
thorough or complete; drastic
a person who supports great social and political change
believing or expressing the belief that there should be great or extreme social or political change:
quantity forming or expressed as the root of another
adj. 根本的；彻底的；极端的,过激的;激进的【数】根的【植】根生的【语】词根的
n. 基础；激进分子；(汉字的)偏旁,部首

例句
These developments have effected a radical change in social life.
这些发展使社会生活发生了根本变化。
I do not share his radical views.
我不同意他的激进观点。
He was a political radical.
他曾是政治上的激进分子
You can look up a character under its radical.
你可以根据部首查找汉字。

普林斯顿公开课 - 人性课程节选
And then when the guests come, we see their ideas and also share and see how people could be very very extreme and radical in their position to Israeli policies.
然后当家里来了客人，我们交流并分享不同的观点,看到一些人的观点会很极端，激进,这体现在他们对以色列政策的看法上。

radial ['reidiəl]
arranged or having parts arranged like rays
having a pattern of lines, etc. that go out from a central point towards the edge of a circle
developing uniformly around a central axis
adj. 半径的；放射状的；光线的；光线状的
n. 射线，光线

radiate ['reidieit]
if a person radiates a particular quality or emotion, or if it radiates from them, people can see it very clearly
to produce heat and/or light, or (of heat or light) to be produced
(of lines, etc.) to spread out in all directions from a central point:
if sth radiates heat, light or energy or heat, etc. radiates from it, the heat is sent out in all directions
vt. 辐射；传播；流露；发射；广播
vi. 辐射；流露；发光；从中心向各方伸展
adj. 辐射状的，有射线的

例句
The electric heater radiated warmth.
电热器散发出热量。
A system of roads radiates from the town center.
一个道路网从镇中心向四面八方伸展出去。
She simply radiated confidence.
她完全是一副信心十足的样子。

eradicate [i'rædikeit]
to pull up by the roots
to do away with as completely as if by pulling up by the roots
to get rid of completely or destroy something bad
vt. 根除，根绝；消灭

例句

The disease has been eradicated from the world.
这种疾病已在全世界得到根除。
These insects are very difficult to eradicate.
这些昆虫很难根除。