| 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. |
| May Day | |
| —n | |
| a. the first day of May, traditionally a celebration of the coming of spring: in some countries now observed as a holiday in honour of workers | |
| b. (as modifier): May-Day celebrations | |