| 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. |
critical crit·i·cal (krĭt'ĭ-kəl)
adj.
Of or relating to a medical crisis.
Being or relating to a grave physical condition especially of a patient.
Of or relating to the value of a measurement, such as temperature, at which an abrupt change in a chemical of physical quality, property, or state occurs.