When you decide to crash at a party and are either;
a) Far too drunk to find yourself a blanket to cover yourself with
b) The awkward stranger who nobody knows at the party and doesn't GET a blanket
c) The only one without a blanket.
So due to lack of blanket, you use your coat for pathetic warmth. Blanket+Coat=Clanket
Drunk Chick: Gurrrrl, I'm about tah fall asleep up in this corner on the hardwood floor, I'm too wasted to get home. You got a blanket ah can useeee?
Technology so advanced in its effects and unexplained in its function that it may as well be magic. Often used by science-fiction fans and authors to refer to technology that's used as "magic in a non-magical setting".
"The reader doesn't need to know how it works, and they understand that the author isn't going to tell them how it works. That's unimportant to the story and would bog things down with irrelevant details... All that matters is that it works and it can do what the story needs."
The "Heisenberg compensators" that make Star Trek's Transporters possible are an example of clarketech, with Gene Roddenberry's answer for how they work being "Very well, thank you".
Taken from Arthur C. Clarke's third law: "Any sufficiently advanced technology is indistinguishable from magic".