互いは英語で
each other

英語の定義

互い
1. n. a mutual relationship, doing with each other
2. n. Usage: This is often used with the honorific 御, お, o- as お互い.

each other
1. 代名詞. （相互代名詞）互い。お互い。

each other
1. pron. (reciprocal pronoun) To one another; one to the other; signifies that a verb applies to two or more entities both as subjects and as direct objects:
Maria and Robert loved each other.