{adj. phr.}, {slang} Pale-faced from fear or sickness; sickly; nauseated. * /Bill's father took him for a ride in his boat while the waves were rough, and when he came back he was green around the gills./ * /The car almost hit Mary crossing the street, and she was pale around the gills because it came so close./ - Also used with other prepositions besides "around", as "about", "at", "under", and with other colors, as "blue", "pink", "yellow", "white".
See: GREEN AROUND THE GILLS.