Blood, the vital fluid
Hemo- (also hema-, hemato-) comes from Greek "haima" (blood) and appears in specialised medical vocabulary. Hemoglobin = the protein that carries oxygen in blood; hematology = the medical specialty of blood study; hemorrhage = severe bleeding (hemo- + rhegnynai = to burst); hemophilia = a disorder in which blood does not clot properly; hematoma = a collection of blood under the skin (a severe bruise). Spanish equivalent "hemo-": hemoglobina, hematología, hemorragia, hemofilia, hematoma.