Green around the gills describes someone who looks ill, especially someone who looks nauseated. Someone who looks green around the gills usually looks pale and may be perspiring. An alternative idiom is green about the gills. Both green around the gills and green about the gills mean the same thing, though the preposition around is used much more frequently. The origin of this idiom is lost, though it seems to have appeared in the mid-1800s. Fish gills are normally red. Presumably, a fish with green gills is a sick fish.
But as world markets are stalked by extreme volatility, the well-fed wealth managers are looking quite green around the gills. (The Financial Times)
Politics, crime and everything else combines to leave us all feeling a little green around the gills most of the time. (The South African)
Some whites have achieved that delicate balance between purity, minerality and freshness, while others are a little green around the gills. Most will be ready to drink young. (The Independent)
Still, she must have been feeling a little green around the gills about her closely watched but increasingly doomed campaign against the well-liked, three-term Republican incumbent, Mike Enzi. (The Los Angeles Times)
Di Natale, sans black turtleneck, was green about the gills after having to side with the government to knock off his party’s own same-sex marriage debate because of, you know, politics. (The Australian Financial Review)
Last year, a photo went viral online of a young boy in a festival crowd, looking rather green about the gills when faced with a naked reveller at a rather unfortunate angle. (The Irish Times)
But sometimes the unintended consequences of going green turn out to mean green about the gills. (The Vancouver Sun)