| zero-point energy
The irreducible minimum energy possessed by a physical system, as of a substance at a temperature of absolute zero. The zero point energy of a vacuum is not zero due to vacuum fluctuations. See Note at absolute zero. |
| 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. |