The act of being a cocky asshole who can't back up their words. Most people who babush also back out of every fight thrown their way. A common hobby of babushers include; getting alaskan pipelines, hard anal sex, and recieving seagulls.
Dude 1: "Tom and Joe were supposed to fight yesterday. What happened?"
Dude 2: " Joe didn't show. He's such a babush."