[交流] Funny English quiz in everyday（NO.19）

Previously
Q:Why did the man put wheels on his rocking chair?

A:Because he wanted to rock and roll.

Today’s Question
What is that which you have never seen, heard or felt, which never existed and still has a name?

We will hold this column everyday, the one who write the right answer first can earned 1 BB.
If u missed it this time, please come on and come here early, then use your smart head to find the answer.
I will give u the right answer in the column tomorrow.
So good luck to u!