IPA: /ˌɪrɪˈdɛntɪzəm/
KK: /ɪrɪˈdɛntɪzəm/
A belief or policy that a country should take control of areas that it believes are historically or ethnically related to it.
The government adopted an irredentism policy to reclaim territories it lost in the past.
Irredentism is formed from "ir-" (meaning not) and "redent" (from Italian "redento", meaning redeemed or recovered) combined with the suffix "-ism" (indicating a doctrine or belief). The term refers to a political principle advocating for the recovery of territories that are considered lost or unredeemed by a nation.
Think of 'not' ('ir-') being combined with 'recovered' ('redent') to remember that irredentism is about the belief in recovering lost territories.