Bags filled with sand, used for protection against floods or as weights.
Sandbags are helpful for keeping water away from homes and buildings during floods.
Examples:
We put sandbags around the house to keep the water out.
The sandbags were heavy and kept the roof from blowing away.
She used sandbags to hold down the tent so it wouldn't fly away.
The sandbags were so heavy, they made the truck slow.
The sandbags were like big, heavy pillows.
The sandbags saved the town from the flood.