the amount of a toxic agent (as a poison, virus, or radiation) that is sufficient to kill 50 percent of a population of animals usu. within a certain time
ldg -abbr
landing
loading
LDH -abbr
lactate dehydrogenase; lactic dehydrogenase
LDL [,el-(,)dē-'el] -n
a lipoprotein of blood plasma that is composed of a moderate proportion of protein with little triglyceride and a high proportion of cholesterol and that is associated with increased probability of developing atherosclerosis called also bad cholesterol
Ldo·pa ['el-'dō-pə] -n
the levorotatory form of dopa that is obtained esp. from broad beans or prepared synthetically, is converted to dopamine in the brain, and is used in treating Parkinson's disease called also levodopa