decay

1. V-I When something such as a dead body, a dead plant, or a tooth decays, it is gradually destroyed by a natural process. 腐坏

The bodies buried in the fine ash slowly decayed. 埋在细灰里的尸体慢慢腐烂了。

2. N-UNCOUNT Decay is also a noun. 腐坏

When not removed, plaque causes tooth decay and gum disease. 牙斑没有清除就会导致蛀牙和牙龈疾病。

3. decayedADJ 腐坏的

Even young children have teeth so decayed they need to be pulled. 连幼儿也有这么严重的龋齿，需要拔掉。

4. V-I If something such as a society, system, or institution decays, it gradually becomes weaker or its condition gets worse. (社会、制度或机构) 衰败

In practice, the agency system has decayed. Most "agents" now sell only to themselves or their immediate family. 实际上，这种代理制已经衰退。现在，大多数“代理人”都只把产品卖给自己或亲近的家人。

5. N-UNCOUNT Decay is also a noun. 衰败

There are problems of urban decay and gang violence. 存在都市衰败和黑帮暴力问题。