an arrest made by a private citizen whose authority derives from the fact of citizenship.
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Origin of citizen's arrest
First recorded in 1950–55
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for citizen's arrest
an arrest carried out by an ordinary member of the public rather than an officer of the law
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012