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Noun: free radical  free'ra-di-kul
  1. 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
    "in the body free radicals are high-energy particles that ricochet wildly and damage cells";
    - radical

Derived forms: free radicals

Type of: atom

Encyclopedia: Free radical