The prefix "Hemo-" refers to blood. There are several synonyms for this prefix such as "hemato-" and "sanguine-". These prefixes are used to describe the various compounds, functions, and processes related to blood. For example, "hematology" is the study of blood and related disorders, "hemoglobin" is the protein molecule in red blood cells that carries oxygen, and "sanguineous" refers to anything containing or relating to blood. Other common medical terms that use variations of "hemo-" include "hemorrhage" (uncontrolled bleeding), "hemostasis" (the process of stopping bleeding), and "hematocrit" (the proportion of red blood cells in the blood).