From Longman Dictionary of Contemporary Englishpaddy wagonˈpaddy ˌwagon noun [countable] American English informalSCP a police vehicle used to carry prisoners
Examples from the Corpus
paddy wagon• It had been an honest mistake, though, the paddy wagon men believing he was dead or dying.Origin paddy wagon (1800-1900) Perhaps from Paddy “Irish person, (Irish) policeman” ((18-21 centuries)), from the male name Paddy, from Irish Gaelic Padraig “Patrick” 