edges of the mouth; corners of the mouth
Refers to the area around the sides of the mouth, often used in descriptions of facial expressions or when food or drink escapes.
When she smiles, dimples appear at the corners of her mouth.
Soup dribbled from the edge of his mouth.
Compound of 口 (kuchi, 'mouth') and 脇 (waki, 'side'). The reading くちわき is a straightforward combination of the two kun'yomi readings.