彼此 (bǐ cǐ) means “each other; one another”. It is an HSK 5 Chinese word in the HSK 3.0 vocabulary.
Practice each character:
我们彼此都很了解对方。
Wǒmen bǐcǐ dōu hěn liǎojiě duìfang.
We both understand each other very well.
Updated: 2026-05-27