verb intr.: To flee, especially without paying one's bills.
The term is a Briticism and its origin isn't confirmed. It's probably from Italian scappare (to escape), influenced by Cockney rhyming slang Scapa Flow, to go. Scapa Flow is an area of water off the northern coast of Scotland, in the Orkney Islands. It was the main British naval base during WW I & II, known for the scuttling of the German fleet.
"I am indebted to the British welfare state; the very one that Mr Cameron would like to replace with charity handouts. When my life hit rock bottom, that safety net, threadbare though it had become under John Major's Government, was there to break the fall. I cannot help feeling, therefore, that it would have been contemptible to scarper for the West Indies at the first sniff of a seven-figure royalty cheque. This, if you like, is my notion of patriotism." — J.K. Rowling; The Single Mother's Manifesto; The Times (London, UK); Apr 14, 2010. www.timesonline.co.uk/tol/