Oxford Dictionary English undercoat noun noun BrE BrE//ˈʌndəkəʊt// ; NAmE NAmE//ˈʌndərkoʊt// [countable, uncountable] Add to my wordlistjump to other resultsa layer of paint under the final layer; the paint used for making this Apply the undercoat first. compare topcoatSee undercoat in the Oxford Advanced American DictionaryCheck pronunciation: undercoat oxfordlearnersdictionaries.com