Several loooong days working on the upcoming issue of mental_floss magazine made me so weary that I flubbed yesterday's Monday Math Square, so we took it down. (That's the excuse I came up with, and I'm sticking with it.) A little better rested today, we're trying again with something short and sweet for Tuesday Test Time. Here we go!

What does the following clue represent?

O _ E R _ T _ O _

Here is the ANSWER.

THE ANSWER:

A PAINLESS OPERATION