class action 
noun Law, North American
A lawsuit filed or defended by an individual acting on behalf of a group: [as modifier]: a class action suit...
- The decision Friday was the result of a class action lawsuit on behalf of half a million sick Florida smokers.
- This takes no account of any liabilities that may be triggered by law suits and class actions against the company and its directors.
- But after the drug was withdrawn, 9,000 lawsuits were filed, many of them as class actions, seeking recovery for millions of individual users and their insurers.