Answer:
Sometimes you feel it weigh a ton. Yet it is nothing, but somehow still there. Makes you uncomfortable around anyone, But speak its name and it's gone.
What you do to determine the length of something
What is found over your head but under your hat?
What eight letter word has "kst" in middle, in the beginning and at the end?
It is in every mountain, it's not in any hill, it's not in all the world, and yet it's in the mill.
When is it bad luck to see a black cat?