green at the gills

東野圭吾の 'The Final Curtain' を読んでいます。

"Detective Matsumiya may have told you that we're interested in the washing of Nihombashi Bridge, an event that takes place every year in July. I collected some photographs. These are some of them." "Oh yeah, I heard about that. It's an interesting idea, even if it does make me go a bit green at the gills. How many pictures did you collect in the end?"

魚のえらを意味する "gill" は知っていますが、"green at the gills" となるとさっぱり見当もつきません。辞書を見ます。

"green at the gills" ではなく、"green around the gills" あるいは "green about the gills" で説明している辞書の方が多かった。

・Collins Dictionary: somewhat pale, as from being sickly, nervous, or frightened: When he heard how much the bill was, he looked a little green around the gills
・Merriam-Webster: pale or sickly in appearance
・Wikctionary: Ill or unwell, especially as indicated by one's appearance.:
・Dictionary.com: Also, green around the gills. Looking ill or nauseated, as in After that bumpy ride she looked quite green about the gills. The use of green to describe an ailing person's complexion dates from about 1300, and gills has referred to the flesh around human jaws and ears since the 1600s. Although in the 1800s white and yellow were paired with gills to suggest illness, the alliterative green has survived them.