| 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. |
| photometry (fō-tŏm'ĭ-trē) Pronunciation Key
The measurement of the intensity, brightness, or other properties of light. Also called photometrics. See also luminous intensity. |