可能来自peak,山峰，即像山峰一样的，委婉语，引申词义消瘦的，有病的，憔悴的。

1. You're looking a little peaky. Are you OK?

你看来有点憔悴。你没事吧？

来自《权威词典》

2. For a while she was peaky and wouldn't eat.

有一阵子她消瘦下去，不想吃什么。

来自辞典例句

3. For a while she was peaky and wouldn't eat. But she was coming around.

有一阵子她消瘦下去,不想吃什么, 但她在恢复过来.

来自辞典例句

4. They tend to be looking a bit peaky and green about the gills.

他们看上去有点憔悴,被吓得脸色苍白.

来自互联网