- (usually initial capital letter) an Italian association that became prominent in 1878, advocating the incorporation into Italy of certain neighboring regions having a primarily Italian population: After World War II, Irredentism faded away in Italian politics.
- the acquisition or annexation of a region previously included in another country because of cultural, historical, ethnic, racial, or other ties, or advocacy for such an acquisition:Few countries are explicitly mandating irredentism, but having ethnic communities divided by borders created by colonialists is hugely troublesome.
