To defoliate a plant or a tree is to make its leaves fall off — and in the sense you are learning, it means doing that with a chemical, a defoliant, not picking the leaves by hand. Farmers may spray cotton or other crops so the leaves drop and machines can pick the fruit more easily.

To defoliate a plant or a tree讓一株植物或一棵樹落葉 is to make its leaves fall off就是讓它的葉子掉光 — and而 in the sense you are learning在你現在學的這個意思裡， it means doing that with a chemical, a defoliant它指的是用一種化學藥劑「落葉劑」來做這件事， not picking the leaves by hand而不是用手把葉子摘掉。 Farmers may spray cotton or other crops農夫可能會噴灑棉花或其他作物 so the leaves drop讓葉子掉落 and而 machines can pick the fruit more easily讓機器更容易採收作物。

Armies have also used defoliants in war, to strip trees so people and paths cannot hide. You will sometimes hear the same verb for insects or disease that leave a tree bare, but the core idea here is: someone puts a defoliant on the plant.

Armies have also used defoliants in war軍隊在戰爭中也用過落葉劑， to strip trees為了讓樹木光禿禿的 so that people and paths cannot hide讓人和路徑無處藏身。 You will sometimes hear the same verb你有時候會聽到同一個動詞 for insects or disease that leave a tree bare用在害蟲或疾病讓樹變光禿禿的情況， but但 the core idea here is這裡的核心概念是： someone puts a defoliant on the plant有人在植物上施用了落葉劑。

It is a formal, technical word.

It is a formal, technical word這是個正式、專業的字。

Everyday English is more likely to say they sprayed the fields, or the trees lost their leaves. Autumn leaf-fall on its own is not this: the tree is not being defoliated; the season is just doing what seasons do.

Everyday English is more likely to say日常英文比較會說 they sprayed the fields他們噴了田地， or the trees lost their leaves或樹掉葉子了。 Autumn leaf-fall on its own is not this單純的秋天落葉不是這個意思： the tree is not being defoliated這棵樹並不是被defoliated； the season is just doing what seasons do季節只是在做季節該做的事。