severe in effect; bad

a serious illness 严重的疾病

There were no reports of serious injuries. 没有接到有人重伤的报告。

The new tax regulations have landed some of the smaller companies in serious trouble. 新的纳税规定使一些较小的公司陷入了严重的困境。

Drugs have become a serious problem in a lot of schools. 吸毒在许多学校已经成了很严重的问题。

This is a very serious offence. 这是非常严重的违法行为。

He's been taken to hospital where his condition is described as serious but stable. 他被送到了医院，医生说他病情严重但是比较稳定。

very ill

not joking or intended to be funny

Please don't laugh - I'm being serious. 请不要笑——我是认真的。

He was wearing a very serious expression and I knew something was wrong. 他一脸严肃，我就知道出问题了。

On the surface it's a very funny novel but it does have a more serious underlying theme. 表面上看，这是一部非常滑稽的小说，但它确实有更为深刻的主题。

A serious person is quiet, thinks carefully about things, and does not laugh a lot.

I remember her as a very serious child. 我记得她是个不爱笑的小孩。

determined to follow a particular plan of action

Is she serious about going to live abroad? 她真的想移居国外吗？

If two people who have a loving relationship are serious about each other, they intend to stay with each other for a long time and possibly marry.

She's had a lot of boyfriends but Simon's the only one she's been serious about. 她有很多男朋友，但西蒙是她唯一真正爱的人。

needing or deserving your complete attention

That's an interesting job offer - I'd give it some serious consideration if I were you. 那是个有意思的工作机会——我要是你的话就会认真考虑一下。

We've got some serious talking to do, you and me. 我们有点重要的事情要谈，就你我两个人。

extreme in degree or amount

We did some fairly serious walking over the weekend. 我们周末走了很多路。

I mean we're talking serious (= a large amount of) money, right? 我的意思是我们在谈很大一笔钱，是吗？

very good of its type

This is a serious wine, Belle, you have to try some. 这是上好的葡萄酒，贝儿，你得尝尝。