プログレッシブ和英中辞典(第4版)の解説
くちうら【口裏・口▲占】
口裏を引いてみる
sound out a person'sfeelings [inner thoughts]
彼の口裏から察すると辞表を出す決心をしたらしい
Judging from what he says, he seems to have made up his mind to resign.
私たち2人は口裏を合せるようにした
We arranged it so that 「we would not contradict each other [we would tell the same story].