蔓延的英文：
to extend
to spread

参考例句：

The eradication of an established infestation is not easy
根除昆虫蔓延是不容易的。

an epidemic outbreak of influenza.
流行性感冒的爆发性蔓延

Vines rambled over the wall.
葡萄藤蔓延于墙上。

The tornado spread destruction.
暴风造成的破坏蔓延开来。

run wild
蔓延;狂暴起来;放肆起来

There's a lot of flu about people are going down like ninepins
流感正在蔓延--传染的人越来越多.

The flu went through the district like a wind
流感很快在这一地区蔓延开。

The broom grows down the arid sandhill.
金雀草蔓延在干燥的沙丘下。

He has an incurable and widespread nepotism.
他们有不可救药的，到处蔓延的裙带主义。

A fireproof wall used as a barrier to prevent the spread of fire.
防火墙，隔火墙作为一道屏障阻止火蔓延的防火的墙。

extend是什么意思：
v. 延长；延伸；扩大；延续；伸，伸出

This will extend the life of the drive.
这样会延长驱动装置的寿命。

Extended consciousness was his line.
延展清醒意识是他的本行。

They extended their citizenship cautiously but steadily.
他们慎重而稳步地扩大授与公民权的范围。

An extended sense of the word honest.
单词honest的引申义

The company's activities are extended.
公司的业务在扩大。

spread是什么意思：
v. （使）扩散，蔓延；展开；摊开；涂；将…分散；分摊；（使）传播，散布
n. 传播；酱；盛宴；伸展；范围；价差；蔓延；分配；多样；横贯两版的篇幅

spreading of a slick
浮油在水面扩展

orienting spreading
定向铺装

Knowledge of the disaster soon spread.
灾难的消息很快传开了。

A cloth should be spread under.
下面该铺一块布。

The news spread abroad.
那消息四处传播。