rot

Rot is the slow breakdown of something over time. You see it in fruit that has gone bad, wood damaged by water, or leaves breaking down on the ground. It often brings to mind bad smells and a soft, ruined texture, but it is also a natural part of life because it helps return dead material to the soil. People also use the word in a figurative way. A plan can be "left to rot" if no one takes care of it, and a group or system can "rot from within" when hidden problems slowly destroy it.

Rot describes the process of decay or decomposition. It often refers to organic matter such as fruit, vegetables, leaves, or dead wood breaking down over time, especially when moisture, age, or bacteria are involved. We also use it for things like teeth or timber when they begin to go bad and lose their strength. Although it can seem unpleasant, rot is an important part of nature because it breaks dead material down and returns nutrients to the soil.

However, "rot" is not limited to physical decay. It is also used figuratively for slow decline, especially when the damage starts inside and spreads. A political system harmed by corruption might be described as "rotting from within." A building, business, friendship, or project can be "left to rot" if people ignore it and let it fall apart. People also say "the rot has set in" when a situation has clearly started to get worse.

There is also a less common noun use, especially in British English, where "rot" can mean nonsense. Someone might say "What rot!" to dismiss an idea as foolish or untrue. This sense is much rarer than the meanings connected with decay and decline, but it still appears in books and older speech.

So whether you are talking about an apple going bad, wood falling apart, a neglected plan, or a corrupt system, "rot" points to a slow process of damage, decay, or decline.