noun
oral slit; oral fissure; rima oris
Medical/anatomical term for the opening between the lips.
口裂の大きさは個人差がある。
The size of the oral slit varies from person to person.
noun
cytostome
Biology term for a cell mouth; see also 細胞口.
See also: 細胞口
原生動物の口裂は細胞口とも呼ばれる。
The cytostome of protozoa is also called a cell mouth.