that which covers the opening of a vessel or box, etc.; a movable cover; as, the lid of a chest or trunk.-the cover of the eye; an eyelid.-the cover of the spore cases of mosses.-a calyx which separates from the flower, and falls off in a single piece, as in the australian eucalypti.-the top of an ovary which opens transversely, as in the fruit of the purslane and the tree which yields brazil nuts.