From Longman Dictionary of Contemporary Englishoil slickˈoil slick noun [countable] TPGTTWa large area of oil floating on the surface of the sea or a river SYN slick
Examples from the Corpus
oil slick• Oil slick prompts no-fishing zone Fishermen have introduced a voluntary ban on fishing in the area surrounding the Shetland oil slick.• Her coffee had an oil slick on top.• The race ended in chaos when three riders drove into an oil slick and skidded off.• Their task will be to help otters and seals which have been contaminated by the seven mile long oil slick.• This problem to some extent overshadowed the oil slick as an environmental issue. 