1. (Science: pathology) The molecular decay or death of a bone, in which it becomes softened, discoloured and porous.
It produces a chronic inflammation of the periosteum and surrounding tissues and forms a cold abscess filled with a cheesy, fetid, puslike liquid, which generally burrows through the soft parts until it opens externally by a sinus or fistula.
2. (Science: dentistry) Another name for cavities due to tooth decay, dental caries.