|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|1.||to relieve (a substance) of pressure or (of a substance) to be relieved of pressure|
|2.||to return (a diver, caisson worker, etc) to a condition of normal atmospheric pressure gradually from a condition of increased pressure or (of a diver, etc) to be returned to such a condition|
decompression de·com·pres·sion (dē'kəm-prěsh'ən)
The relief of pressure on a body part by surgery.
The restoration of deep sea divers and caisson workers to atmospheric pressure by means of a decompression chamber.