|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
|chronometer (krə-nŏm'ĭ-tər) Pronunciation Key
An extremely accurate clock or other timepiece. Chronometers are used in scientific experiments, navigation, and astronomical observations. It was the invention of a chronometer capable of being used aboard ship, in 1762, that allowed navigators for the first time to accurately determine their longitude at sea.