WordundirdjúpiðMeaningthe deepPart of speechnounPronunciationCourseIcelandicLessonAccusative of extentUsages of undirdjúpiðVið sáum kafbátinn sökkva í undirdjúpið.We saw the submarine sink into the deep.Þykki skrokkurinn verndar okkur í undirdjúpinu.The thick hull protects us in the deep.