| 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. |
| baryon (bār'ē-ŏn') Pronunciation Key
Any of a family of subatomic particles composed of three quarks or three antiquarks. They are generally more massive than mesons, and interact with each other via the strong force. Baryons form a subclass of hadrons and are subdivided into nucleons and hyperons. Protons and neutrons are baryons. See Table at subatomic particle. |