When one person is to a point of being so tired, that there mind is half way between dream world and reality, causing them to possibly see things that aren’t there or say things they normally wouldn't
"Hey, why did you say you wanted to eat my cat last night?"
"Sorry, I didn't mean it, I was tired high... couldn't get much sleep."
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."