a workman who doesn't do much apart from scratch his balls

Over-The-Pants-Hand-Job. Distant cousin of the dry hump.

A problem with a degree of difficulty greater than that of the average "head scratcher."

one who itches his little testicles in public.

A golf player scratching the golfball for cleaner balls... And more precise shots..

another slang for prescription pain killers oxycontin, when taken, itching of the balls occur while feeling high.