|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
|a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.|
|chitin (kīt'n) Pronunciation Key
A tough, semitransparent substance that is the main component of the exoskeletons of arthropods, such as the shells of crustaceans and the outer coverings of insects. Chitin is also found in the cell walls of certain fungi and algae. Chemically, it is a nitrogenous polysaccharide (a carbohydrate).