He is backing off from the argument.

Back when I was a child, we used to play outside all day.

I remember back when we used to play in the park every day.

I love you to the moon and back.

I helped you, now it's back atcha.

I'm ready for the challenge, back at ya!

He always backs down when faced with a challenge.

He backs away from the dangerous dog.

She shrinks back in fear when she sees a spider.

She always knows how to clap back at her critics.