When things such as dead plants or animals decompose, or when something decomposes them, they change chemically and begin to decay.
双语例句
例： a dead body found decomposing in the woods.
在树林里发现的一具正在腐烂的死尸。
例： The debris slowly decomposes into compost.
这堆碎屑慢慢地分解变成了堆肥。