undercoatPronunciation: /ˈʌndəkəʊt/Translate undercoat | into French | into German | into Italian | into Spanish Definition of undercoat noun 1a layer of paint applied after the primer and before the topcoat: the woodwork was primed and had two undercoats 2an animal’s underfur or down. verb [with object] apply an undercoat of paint to: she was busy undercoating the bookshelvesundercoat in other Oxford dictionaries Definition of undercoat in the US English dictionary