aufeinander

on each other, at each other, with each other

adverb Rare #27,035
on each other, at each other Often used with verbs of attack or conflict in expressions such as aufeinander losgehen (to attack each other) and aufeinander herumhacken (to keep picking on each other).
GE: Die Kinder werfen sich Schneebälle aufeinander.
EN: The children are throwing snowballs at each other.
on each other, with each other Used in expressions such as aufeinander aufpassen, meaning to look out for one another.
GE: Wir müssen aufeinander aufpassen.
EN: We have to look out for one another.

Ich sage, wir gehen alle, dann können wir aufeinander aufpassen.

I say we all go, then we can look out for each other.

— The Flowers of War (2011)

Dann gehen sie aufeinander los.

Then they turn on each other.

— Hass (1995)

Die Passagiere gehen aufeinander los.

The passengers are attacking each other.

— Train to Busan (2016)

Stellt doch die Koffer nicht alle aufeinander, wie soll man denn da auspacken?

Don’t pile all the suitcases on top of each other—how are we supposed to unpack them?

— The Blue Angel (1930)

Dieses Wochenende treffen die beiden stärksten Teams aufeinander.

This weekend the two strongest teams meet.

Wir müssen aufeinander aufpassen.

We have to look out for each other.

— Brother 2 - Brat 2 (2000)

Die Mädchen hacken schon wieder aufeinander herum.

The girls are picking on each other again.

Wir dürfen stolz aufeinander sein.

We can be proud of each other.

— Pappa ante Portas (1991)

Wir gehen aufeinander zu.

We’re walking toward each other.

— Phoenix (2014)