| Napier's bones | |
| —pl n | |
| a set of graduated rods formerly used for multiplication and division | |
| [C17: based on a method invented by John | |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |
| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. |