decayed

Decayed is the past participle of decay and is used as an adjective to describe something that has deteriorated, decomposed, or degraded. The word derives from Latin dēcādere, “to fall away,” via Old French and English adoption.

In biology and everyday life, decay commonly refers to the decomposition of organic matter by microorganisms, enzymes, and chemical reactions. This process depends on moisture, temperature, oxygen, and the presence of decomposers such as bacteria and fungi. Decay proceeds through stages from initial deterioration to advanced breakdown, often producing characteristic odors and textures. It is central to nutrient cycling in ecosystems and is a concern in food storage and waste management.

In dentistry, tooth decay, or dental caries, describes the gradual destruction of tooth tissue by acidic byproducts of bacteria in dental plaque. Left untreated, decay can reach the inner tooth structures and cause pain or infection. Prevention includes regular oral hygiene, fluoride exposure, and reducing fermentable carbohydrates; treatment ranges from filling decayed areas to root canal therapy or extraction.

In physics, radioactive decay describes the spontaneous transformation of unstable atomic nuclei into more stable forms, emitting radiation in the process. Decay is characterized by a half-life and is probabilistic at the level of individual atoms but predictable statistically for large samples. Common decay modes include alpha, beta, and gamma decay, each yielding different products and penetrative properties.

In mathematics and related fields, decay describes a decrease in a quantity over time or distance, such as exponential decay in signal strength or population models. The term is used across disciplines to denote decline, deterioration, or the loss of activity.