a maritime region in W South America: long in dispute between Chile and Peru; annexed by Chile 1883; divided as a result of arbitration 1929 into a Peruvian department (Tac·na) and a Chilean department (Arica).
See also Tacna-Arica a port in extreme N Chile: awarded to Chile in 1929 after the lengthy Tacna-Arica dispute with Peru; outlet for Bolivian and Peruvian trade. Pop: 180 000 (2005 est)