形容詞 frivolous:

1. not serious in content or attitude or behavior

1. If I could intrude a note of seriousness into this frivolous conversation ...
   我真想說(shuō)一句，叫他們談話(huà)放嚴(yán)肅些 ...
2. I think there is a kernel of truth in these otherwise frivolous comments.
   我認(rèn)為在這些本來(lái)是無(wú)關(guān)緊要的評(píng)論中含有一定的真實(shí)性。
3. At 18, he's still rather frivolous and needs to grow up.
   他到了十八歲仍然很不懂事，很不成熟。
4. She thought that reading romantic novels was a frivolous way of spending her time.
   她認(rèn)為看浪漫小說(shuō)是虛度時(shí)光。

friv.o.lous

adj.（形容詞）
Unworthy of serious attention; trivial:
無(wú)關(guān)緊要的：不值得認(rèn)真注意；不重要的：
例句：
a frivolous novel.
一部無(wú)關(guān)緊要的小說(shuō)

Inappropriately silly:
輕率的：
例句：
a frivolous purchase.
輕率購(gòu)買(mǎi)的東西

來(lái)源：
Middle English
中古英語(yǔ)
probably from Latin frovolus [of little value]
可能源自 拉丁語(yǔ) frovolus [價(jià)值很小的]
probably from fri3re [to crumble]
可能源自 fri3re [弄成碎屑]

【引伸】
friv.olously
adv.（副詞）
friv.olousness
n.（名詞）