1. Word combination: doorway, opening, spout, taste, tone, slogan, verbal calculation, mouth, entrance, wellhead, crossing, knife edge, word of mouth, mouth cup, confession, tongue and tongue, neckline, excuse and interface.

2. Spoken Chinese, standard first-class words (commonly used words). Ideographic characters, whose Oracle Bone Inscriptions is like an upward mouth shape, are meaningful in the upper part, so they are often used to refer to pronunciation. The original meaning is mouth, which is extended to the place where the container passes outward, the place where it enters and exits, and so on. Mouth is also a radical word.