Zarf: An insulating sleeve that fits around a cup to make it more comfortable for the drinker to hold—which is to say that plastic or cardboard sleeve that coffee shops slide around their disposable cups.
My sister actually has a quilted zarf that she carries with her to slide around disposable cups. Aurora and I tried to convince her that she ought to get a reusable cup instead—she’d cut down on her disposability quotient quite a bit more by reusing the cup than she does by reusing the zarf. Plus, though it drastically reduces the opportunities one has to introduce the word zarf into conversation, the discounts offered by coffee shops for using your own mug will generally allow that mug to pay for itself within a dozen visits. She says that she would lose a reusable travel mug, and therefore it wouldn’t pay for itself ever.
It’s true that on occasion I have dropped, left, or otherwise lost a travel mug. On the other hand, I also have picked up, discovered, or otherwise found replacements. For instance, my mug that I’m using today came to me from Carnegie Mellon’s Portugal campus via a Forbes Avenue street corner where it had been forgotten. It’s quite a bit nicer than the mug I left in Berlin, PA three days before I found it. Easy come, easy go, as my grandfather used to say. These things tend to have a way of evening themselves out.