Gurney - basically a plaster such as is used to fill holes in walls, specially formulated to get rid of 'workman's bum', that portion of butt cleavage that can show when a well padded man bends over. Spread it on, dry it off with a hair dryer and it stays there until you want it gone.

Quite funny, but I don't quite get why the warning on the screen. There's nothing there that isn't seen quite regularly on building sites!