the position of the football player in the backfield who directs the offensive play of his team; "quarterback is the most important position on the team"
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"
a telecommunication system that transmits images of objects (stationary or moving) between distant points
broadcasting visual images of stationary or moving objects; "she is a star of screen and video"; "Television is a medium because it is neither rare nor well done" - Ernie Kovacs
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