a hemoprotein composed of globin and heme that gives red blood cells their characteristic color; function primarily to transport oxygen from the lungs to the body tissues; "fish have simpler hemoglobin than mammals"
any of a large variety of proteins normally present in the body or produced in response to an antigen which it neutralizes, thus producing an immune response
line thrown from a vessel that people can cling to in order to save themselves from drowning
line that raises or lowers a deep-sea diver
support that enables people to survive or to continue doing something (often by providing an essential connection); "the airlift provided a lifeline for Berlin"; "she offered me a lifeline in my time of grief"