serious这个单词的反义词是哪个单词

relaxed，relaxing 放松的

1、同义词：dangerous，grave，grievous，life-threatening，severe，goodsober，unplayful。

2、反义词：frivolous，playful

例句：

The mistake is not very serious.    这错误不太严重。

Getting married is a serious matter.结婚是件大事。

He is a serious boy.他是个严肃的孩子。

I was pretty serious in what I said at dinner.我晚餐时说的话是当真的。

The play was amusingly written， but its subject was a serious one.    剧本写得风趣逗笑，但其主题则是严肃的。