v., -cayed, -cay·ing, -cays. v.intr.
- 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.
n.
- 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.
[Middle English decayen, from Old French decair, from Vulgar Latin *dēcadere : Latin dē-, de- + Latin cadere, to fall.]
decayer de·cay'er n.SYNONYMS decay, rot, putrefy, spoil, crumble, molder, disintegrate, decompose. These verbs refer to gradual change resulting in destruction or dissolution. Decay can denote partial deterioration short of complete destruction: Brush and floss regularly to prevent teeth from decaying. Rot is sometimes synonymous with decay, but often, like putrefy, stresses offensiveness to the sense of smell: The food left on the counter began to rot. Arctic cold prevented the prehistoric animal from putrefying. Spoil usually refers to the process by which perishable substances become unfit for use or consumption: Put the fish in the refrigerator before they spoil. Crumble implies physical breakdown into small fragments or particles: The ancient church had crumbled to ruins. To molder is to crumble to dust: The shawl had moldered away in the trunk. Disintegrate refers to complete breakdown into component parts: The sandstone façade had disintegrated from exposure to the elements. Decompose, largely restricted to the breakdown of substances into their chemical components, also connotes rotting and putrefying, both literally and figuratively: "trivial personalities decomposing in the eternity of print" (Virginia Woolf).
