The Serbo-Croatian word krajina derives from Proto-Slavic *krajina, derived from *krajь, meaning "edge", related to *krojiti, "to cut"; the original meaning of krajina thus seems to have been "place at an edge, fringe, borderland", as reflected in the meanings of Church Slavonicкраина, kraina, and Old East Slavicокраина, okraina.
In some South Slavic languages, including Serbo-Croatian and Slovene, the word krajina or its cognate still refers primarily to a border, fringe, or borderland of a country (sometimes with an established military defense), and secondarily to a region, area, or landscape. The word kraj can today mean an end or extremity, or region or area. Archaically extrapolated, it could mean "army" or "war"; this meaning developed from the earlier meaning of "borderland" in a manner analogous to the French word campagne. The term is equal to GermanMark and Frenchmarche.
Bosanska Krajina, around Banja Luka and encompassing a larger area, also on older maps called Turkish Croatia; westwards from Vrbas river, on the NW from Završje (on older maps, Završje is a part of Croazia Turca, Türkisch Kroatien, Török Horvátország )
SAO Kninska Krajina, Kninska Krajina since the Yugoslav wars is used by some to signify two regions Knin and its surroundings, and to a larger extent Krajina proper (referring to main portion of Republic of Serb Krajina).
^ abRick Derksen (2008), Etymological Dictionary of the Slavic Inherited Lexicon, Brill: Leiden-Boston, page 244
^ abcde“*krajina” in Oleg Trubačóv (ed.) (1974–), Этимологический словарь славянских языков [Etymological dictionary of Slavic languages], Moscow: Nauka, volume 12, pages 87-88
^Max Vasmer (1986), Etimologičeskij slovarʹ russkogo jazyka [Etymological Dictionary of the Russian Language], in 4 vols (second ion), Moscow: Progress — Translated from German and supplemented by O. N. Trubačóv
^ abGroup of authors (1969). "Кра̏јина". Речник српскохрватскога књижевног језика, vol. 3 (in Serbo-Croatian). Novi Sad/Zagreb: Matica srpska/Matica hrvatska. p. 30.
^Group of authors (1972). "Krajina". In colonel-general Nikola Gažević. Vojna enciklopedija, vol. 4 (in Serbo-Croatian). Belgrade. p. 681.
Karlo Jurišić, Lepantska pobjeda i makarska Krajina, Adriatica maritima, sv. I, (Lepantska bitka, Udio hrvatskih pomoraca u Lepantskoj bitki 1571. godine), Institut JAZU u Zadru, Zadar, 1974., str. 217., 222., (reference from Morsko prase)