Alternative reference for 'testicles and scrotum', most often mentioned after a man gets out of a long, hot, steamy shower. After extended exposure to high heat and humidity the ball sac gets loose, resembling chewed bubble gum that has been stretched out and covered in pubes.
After his time in the sauna, Larry's hairy gumbers were slapping the inside of his knees.
To take something small, that doesn't quite qualify as a theft. Probably from the Danish "skæv" or the Dutch "scheef", both of which are pronounced similarly, meaning "askew, or not quite right'. To change an item's ownership without permission, but only something small and of little worth.
"I skeefed an apple off the neighbor's tree." "I skeefed some chips outta your bag when you looked away." "Don't skeef my chair when I go to the bathroom."