1
a radical
可数名词，指主张极端变革的人。
He is considered a radical.
他被视为一个激进分子。
激进分子
先理解核心含义，再看它在真实句子里的用法。
激进分子
A person who has radical ideas or opinions, especially one who wants complete social or political change.
He is considered a radical.
他被视为一个激进分子。
(数或量的)根。
A root (of a number or quantity).
基团
(chemistry) two or more atoms bound together as a single unit and forming part of a molecule
表意文字(如汉字)中用于检索字的部分；通常也表义,但并非总是如此；参见下义。
In logographic writing systems such as the Chinese writing system, the portion of a character used to index it. Often, but not always, this is also the portion indicating meaning; compare the following sense.
自由基
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
The radical was arrested for protesting against the government's new policy.
这名激进分子因抗议政府的新政策而被捕。
AI contextual example
A free radical is a highly reactive atom or molecule that can damage cells.
自由基是一种高反应活性的原子或分子，会损害细胞。
AI contextual example
In mathematics, the radical of a number is its square root or nth root.
在数学中，一个数的根是其平方根或n次方根。
AI contextual example
in the body free radicals are high-energy particles that ricochet wildly and damage cells
在体内,自由基是高能粒子,它们横冲直撞,损伤细胞
WordNet
可数名词，指主张极端变革的人。
He is considered a radical.
他被视为一个激进分子。
常用复数形式，化学术语。
Free radicals are highly reactive.
自由基具有高度反应性。
数学符号，用于表示开方运算。
The radical sign indicates the square root.
根号表示平方根。
Not this
He is a radical person.
Use this
He is a radical.
中文'激进分子'已包含'分子'，英语中名词radical直接指人，无需再加person。
Not this
The radical of 9 is 3.
Use this
The square root of 9 is 3.
数学中表示平方根通常用square root，radical虽可指根号但更常指根式或激进分子，此处用法不标准。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
政治激进分子
He was labeled a political radical for his extreme views.
他因极端观点被贴上政治激进分子的标签。
激进活动家
The radical activist organized a protest against the new law.
这位激进活动家组织了一场抗议新法律的行动。
自由基
Antioxidants help neutralize free radicals in the body.
抗氧化剂有助于中和体内的自由基。
自由基反应
This chemical process involves a radical reaction mechanism.
这个化学过程涉及自由基反应机理。
根号
Write the square root using a radical sign.
用根号写出平方根。
根式
Simplify the radical expression to its lowest terms.
将根式化简为最简形式。
Use radical naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
联想 radical 中的 rad 像 root（根），助记'根'（数学根号、化学自由基）。
多用于政治讨论或媒体报道，指持有极端改革观点的人，语气可能中立或略带批评。
These words share the spelling ending 'ical' but do not rhyme with 'radical' because the stressed vowel sounds differ. 'Radical' has /æ/ in the first syllable, while these words have /ɛ/, /ɪ/, /ə/, etc. They are useful for comparing spelling patterns only.
Dictionary facts from DICTIONARY_API_DEV, ECDICT, WIKTIONARY.