懈怠的英文：
keep a slack hand
laches
nonfeasance
slacken off

参考例句：

Don't slack off in your studies.
学习上不可懈怠。

If at first you don't succeed, try, try again.
初试不成功，努力勿懈怠。

"Therefore, translators and interpreters cannot afford to be lazy."
因此，翻译员和通译员不可懈怠。

Incapable or seemingly incapable of being fatigued;tireless.
不懈怠的不能或看起来不能疲倦的;不知劳累的

Don't relax your efforts because the examinations are over.
不要因为考试已过便懈怠你的努力。

He had never let a foreman see him slacking.
他从未在哪个工头面前表现出丝毫懈怠。

Bill was kicked out of the military for being a slacker.
比尔因懒惰懈怠而从军队里被赶了出来。

keep是什么意思：
v. 保持，处于；继续，重复；使耽搁；抚养；履行
n. 生活费，生活必需品

That news will keep.
那个消息留待以后再宣布。

They keep a shop.
他们经营一家商店。

How are you keeping?
你最近还好吧？

slack是什么意思：
n. 煤屑；宽松裤
adj. 松弛的；疏忽的；清淡的
v. 松懈，放松，使缓慢

The slacks have an elastic waistband.
这条便裤的腰带可伸缩。

Not taut, firm, or compact; slack.
松弛的不紧、不严密或不坚实的;放松的

I have never saw a pair of slacks that have very much slack in them.
我从未见过裤子上有多少松垂之处。

laches是什么意思：
n. 懈怠,疏忽