scrape- to intrude on someone else's private conversation when they are not wanted. If someone is known to 'scrape' often and does it many times they become known as a scrapegoat. Therefore when that person tries to start conversation with a group of people, without actually scraping somebody will tell them they should "scrape out". This mean that anytime the person known as a scrapegoat they are 'scraping even though they might not be, its just everybody takes joy in calling them a scrape.
"hey everyone, what were you talking about"
"scrape out you scrapegoat"