If something is sprawlier, it is more spread out and takes up more space.
Sprawlier things might seem messy or hard to control.
Examples:
The garden is getting sprawlier and sprawlier.
The new house is much sprawlier than the old one.
The city is getting sprawlier every year.
My room is getting sprawlier and sprawlier with all my toys.
The dragon's tail was getting sprawlier and sprawlier as it grew.
The jungle is getting sprawlier and sprawlier as we walk deeper into it.