A large bag, often made of strong material, used for carrying or storing things.
Sacs are very useful for carrying lots of things at once.
Examples:
She puts all her clothes in the sac.
He carries his toys in the sac.
The sac is heavy because it has lots of things inside.
The big sac looks like a giant pillow.
I have a sac that can carry all the books in the world.
The sac is as big as a house.