free radicalˌfree ˈradical noun [countable] technical 
an atom or group of atoms with at least one free electron, which combines with other atoms very easily: 
It is thought that free radicals can damage cells.
an atom or group of atoms with at least one free electron, which combines with other atoms very easily: It is thought that free radicals can damage cells.- great-
- Great Barrier Reef
- Great Bear
- Great Britain
- greatcoat
- Great Crash
- Great Dane
- Great Depression
- Great Divide
- Greater London
- Greater London Authority
- Greater Manchester
- Great Exhibition
- Great Expectations
- Great Fire of London
- Great Gatsby, The
- Great Lakes
- Great Leap Forward
- greatly
- greatness
- Great Ormond Street Hospital
- Great Plains
- Great Rift Valley
- Great Salt Lake
- Great Seal of the United States