| a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison. |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
| Leibniz (līb'nĭts) Pronunciation Key
German philosopher and mathematician who invented the mathematical processes of differentiation and integration, which greatly expanded the field of calculus. Leibniz also established the foundations of probability theory and conceived the idea for a practical calculating machine. |