A flashlight
holes
A hole
A Balloon pusy
A carol rhymes with barrel and is something you sing.
carol
Helium is a gas that is weightless, odourless, and would make a barrel lighter.
A hole
A hole. When you put a hole in the barrel, it reduces the weight of the barrel. But, when you remove the hole, the barrel becomes heavier.
holes
Helium.
A hole. A hole cannot be seen, weighs nothing, and when added to a barrel, it reduces the weight of the barrel without adding any weight itself.
a hole
The answer is a hole.
A hole. A hole cannot be seen, doesn't weigh anything, but when placed in a barrel it reduces the overall weight by displacing some of the volume of the material the barrel can hold.
A hole
You can put a hole in the wooden box to make it lighter by reducing the amount of material in it.
Less.