What it means
The beginning of words for something that comes in two or happens twice. Diplopia is double vision (seeing two of everything), and a disaccharide is a sugar made of two sugar units. Do not mix it up with dia-, which means through or across, as in dialysisdy-AL-ih-sisA treatment that removes wastes and extra fluid from the blood when the kidneys can no longer do it.dia- through, apart-lysis separation, looseningFull entry and diarrhea.