From Longman Dictionary of Contemporary Englishchain gangˈchain gang noun [countable] SCJa group of prisoners chained together to work outside their prison
Examples from the Corpus
chain gang• Tethered like a chain gang, the herd is led away between koonkies.• He did a stint on a chain gang, and he became a professional boxer for a while.• This is the guy who, in the first half, was moving as gracefully and quickly as an Alabama chain gang.• Citizens have loved his reintroduction of the chain gang and the Army-surplus tents he erected to ease jail overcrowding. 