Was heißt decay? Was heißt decay? Biology To break down into component parts; rot.Physics To disintegrate or diminish by radioactive decay.Electronics To decrease gradually in magnitude. Used of voltage or current.Aerospace To decrease in orbit. Used of an artificial satellite.To fall into ruin: a civilization that had begun to decay. Pathology To decline in health or vigor; waste away.To decline from a state of normality, excellence, or prosperity; deteriorate.To cause to decay.The destruction or decomposition of organic matter as a result of bacterial or fungal action; rot.Rotted matter.Physics Radioactive decay.Aerospace The decrease in orbital altitude of an artificial satellite as a result of conditions such as atmospheric drag.A gradual deterioration to an inferior state: tooth decay; urban decay. A falling into ruin.