Oxford Dictionary English mouthguard nounnoun BrE BrE//ˈmaʊθɡɑːd// ; NAmE NAmE//ˈmaʊθɡɑːrd// (North American English) (British English gumshield) Add to my wordlistjump to other resultsa cover that a sports player wears in his/her mouth to protect the teeth and gumsSee mouthguard in the Oxford Advanced American DictionaryCheck pronunciation: mouthguard oxfordlearnersdictionaries.com