私下sīxiàin private; privately; behind closed doorsHSK 7-9PronunciationsīxiàExample sentence他们私下商量了这件事的解决办法。Tāmen sīxià shāngliang le zhè jiàn shì de jiějué bànfǎ.They discussed the solution to this matter in private.Read and choose an answerOne fixed sampleExplore a sample