down in (at) the mouth 垂头丧气

from mouth to mouth 口口相传，广泛流传

put words in (to) someone's mouth 教人怎么说，诬指某人说过某话

stop someone's mouth 使某人缄默

take the words out of someone's mouth 抢先说某人想说的话

from the horse's mouth （消息等）第一手的，直接得来的，来源可靠的

in the mouth of 出于……之口

make a mouth 做鬼脸

open one's mouth wide 狮子大开口（指索高价）；信口开河