radical

noun
  1. A person who advocates for thorough or complete political or social reform; a member of a political party or part of a party pursuing such aims. noun
    The radicals in the group pushed for immediate and sweeping changes.
    He was considered a radical for his unconventional views on education reform.
  2. Relating to or affecting the fundamental nature of something; far-reaching or thorough. adjective
    The company underwent a radical transformation to stay competitive.
    Radical changes in the law have been proposed to address the issue.
  3. In mathematics, a quantity forming or expressed as the root of another. noun
    The radical sign indicates the square root of a number.
    Simplifying radicals is a common task in algebra.
  4. In linguistics, relating to the root of a word. adjective
    The radical part of the word 'unhappiness' is 'happy'.
    Understanding the radical helps in deciphering the meaning of complex words.
  5. In chemistry, a group of atoms behaving as a unit in a number of compounds. noun
    The hydroxyl radical is highly reactive.
    Free radicals can cause damage to cells in the body.