diastema
/ˌdaɪəˈstiːmə/noun
(pl. diastemata)
1- a gap between the teeth, in particular齿隙, 尤指：
1.1
- Zoology a space separating teeth of different functions, especially that between the biting teeth (incisors and canines) and grinding teeth (premolars and molars) in rodents and ungulates【动】齿隙, 牙间隙。
1.2
- a gap between a person's two upper front teeth（人的）上门齿间的间隙。
词源
mid 19th cent.: via late Latin from Greek diastema 'space between'.