Basically, the Original Content of the material you are going to use. In novel/manga/anime/game/etc....basically, the Original Language of the content. In novel specifically, the Original Language of the chapter.
Uncooked meat are called raw meat. Unprocessed materials are called raw materials. Untranslated chapters are called raw chapter. Enjoy your English word of the Day.
or maybe those are not the answers you are looking for. . . this types also come out on novels specially on R-18 types. . . it means no rubber or protection. . .
Just like the steak you had come from raw meat. the translated novel we read comes from raw material still in their original language.