opening; mouth (of a container)
Refers to the opening or mouth of a bag, bottle, or similar container.
Please close the opening of the bag tightly.
mouth area; area around the mouth
Refers to the area around a person's or animal's mouth.
I gently wiped the baby's mouth area.
Compound of 口 (kuchi, 'mouth') and 部分 (bubun, 'part').