|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|aplastic anemia (ā-plās'tĭk) Pronunciation Key
A form of anemia in which the capacity of the bone marrow to generate red blood cells is defective. Aplastic anemia may be caused by bone marrow disease or exposure to toxic agents, such as radiation, chemicals, or drugs.