Ironsides iron·si·des US/ˈaɪɜrˌnsaɪdz/ uncommon noun 1. English general and statesman who led the parliamentary army in the English Civil War (1599-1658) SynonymsCromwellOliver Cromwell Related words Broader terms generalstatesman WordNet 2.1 (Princeton University). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved.