English to English

noun (n)

• 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(noun.substance)

  Example:
  In the body free radicals are high-energy particles that ricochet wildly and damage cells.
  

  Synonym:
  radical
  

  source: wordnet30