提示：点击例句中的单词，就可以看到词义解释

The signs of something indefinably but seriously wrong .

很严重但又难以说清的问题的迹象。

My first impression was indefinably unpleasant .

我的初次印象是一种说不清的不愉快。

She was indefinably depressed as they walked homeward .

当他们走上归途时，她却莫名其妙地变得消沉了。