Word Study
irredentist
CIDE DICTIONARY
irredentist, n.
an advocate of irredentism, especially a person in one country who advocates the incorporation of a region in another country related historically to his country. [WordNet 1.5]
OXFORD DICTIONARY
irredentist, n. a person, esp. in 19th-c. Italy, advocating the restoration to his or her country of any territory formerly belonging to it.
Derivative
irredentism n.
Etymology
It. irredentista f. (Italia) irredenta unredeemed (Italy)
For further exploring for "irredentist" in Webster Dictionary Online