严密的英文：
strict
tight

参考例句：

We keep a close watch on the prisoners.
我们严密看守囚犯。

The would-be murderer was kept under close watch.
那个有行凶企图的人受到于严密的监视。

Sufficient care was had to the safekeeping of the captive without inflicting on him any unnecessary suffering.
为了防止俘虏逃跑，他们采取了严密的措施，但是也不给他不必要的罪受。

To keep watch and ward
严密看守

A rigid distinction
严密的区别

Cold logic
逻辑严密

Clearly and exactly defined;precise
明确的;严密的;精确的

A watertight alibi;a watertight contract.
无懈可击的借口;严密的合同

Tighten up security
使安全措施更严密.

loose thinking
不严密的思想

strict是什么意思：
adj. 严格的；严厉的；严谨的；精确的；完全的；周密的

follow a strict diet
严格遵照饮食规定

She is strict in the matter of discipline.
她对纪律的要求是严格的。

There are strict controls on immigration into this country.
移民到这个国家有严格的限制。

follow a strict regimen
严格地遵守养生之道

Henry is a person of strict morality.
亨利是个品行极其端正的人。

tight是什么意思：
adj. 牢的，紧的；紧贴的；紧凑的；不漏的；吝啬的
adv. 紧紧地；牢固地

tightness of warp
经纱紧密度

Stretch the rope tight, please.
请把绳子拉紧。

Uncomfortably tight and confining.
不适地紧绷的，不适地束缚的

He is in a tight spot.
他处境艰难。

These jeans are too tight in the crotch.
这些牛仔裤的裤裆太紧了。