each other
US /iːtʃ ˈʌð.ər/
UK /iːtʃ ˈʌð.ər/

1.
друг друга, друг другу
used to show that each of two or more people or things does something to the other or others
:
•
They love each other very much.
Они очень любят друг друга.
•
We help each other with our homework.
Мы помогаем друг другу с домашним заданием.