Added 9 October 2026 unionism noun Categories: SocietyUncommon Words noun ! Definition from Wiktionary (CC BY-SA). More about unionism at Wordnik → Where our words come from → The support of advocacy of a union, especially of a trade union. Support for the North (the Union) during the American Civil War. Support for the continuance of the United Kingdom (especially with respect to Northern Ireland). Related Words: societyunionprofessionlabourcollectivismtrade-unionismsyndicalismassociationismlabourismmutualismantiunionism Back to today's word