any unpleasant thought and/or mental image (ie family members, global disasters, priests, etc.) that comes into your mind right at the moment of ejaculation.
"Dude, Rob pulled me aside just to tell me he got cumkill last night."
"What exact form of cumkill?"
"Father Flannigan."
"Dude. Sick."
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."