dental damBrE /ˈdentl dæm/ 🔊NAmE /ˈdentl dæm/ 🔊 (also dam) nouna small rubber sheet used by dentists to keep a tooth separate from the other teeth 橡皮障（牙医用的牙齿阻隔膜）a small rubber sheet used to protect the mouth during sex （性交时用的）口腔保护膜；口交保险膜