1. people who support extreme political or social changes
2. atoms or groups of atoms that have unpaired electrons and are highly reactive
Usage: chemistry
3. mathematical expressions under a radical sign, especially square roots
Usage: mathematics

Examples

• The political radicals demanded immediate reform of the government.
• Young radicals organized protests against the war.
• Free radicals in the body can cause cellular damage.
• The chemist studied how radicals form during the reaction.
• Students learned to simplify expressions containing radicals.
• She memorized the most common Chinese radicals to help with reading.
• The dictionary organizes characters by their radicals.