oilskinPronunciation: /ˈɔɪlskɪn/Definition of oilskin noun [mass noun] heavy cotton cloth waterproofed with oil: a fisherman’s outfit of yellow oilskin [as modifier]:an oilskin coat (oilskins) garments made of oilskin. oilskin in other Oxford dictionaries Definition of oilskin in the US English dictionary