He was improperly dressed for the occasion.

他的衣着不大适合这个场合。

《牛津词典》

They were unsuitably dressed for the occasion.

他们的穿着在那种场合很不得体。

《牛津词典》

We were expecting a live band for the occasion which is always fun, but apparently this has been cancelled due to illness.

我们本来期待着一个一直以来都很有趣的临时现场演奏，但显然因为乐队成员生病已经被取消了。

youdao

Australian rock heavyweight Midnight Oil has been reformed for the occasion.

VOA: standard.2009.03.14

But first we need to establish a few things about the occasion for this piece and about the genre, the literary genre of the mask in general.

但首先我们必须建立一些,关于此作品与流派，一般文学体裁《面具》的场合。

耶鲁公开课 - 弥尔顿课程节选

So we have to assume that the occasion for this poem is some kind of question posed by John Milton, Sr., a question like, "To what end am I supporting you, Son?

我们可以假定这个诗的起因是,老约翰弥尔顿问小弥尔顿，“我到底为什么要资助你，儿子？“

耶鲁公开课 - 弥尔顿课程节选

They gathered aboard the Silver Whisper cruise liner moored for the occasion on the Neva River.

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Glasgow Rangers have pledged to bring some of their first-team squad down for the occasion.

BBC: Glasgow Rangers play Corby to mark official opening

It implies that you should dress well, but appropriate for the occasion or the corporate culture.

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