Built-up means covered with buildings rather than open ground. A built-up area, heavily built-up.
In British law a built-up area is defined by street lighting, and that sets the speed limit at thirty. The definition catches people out, since the lamps rather than the houses decide it.
1adjectivebuilt-upCovered with buildings rather than open ground.
“The limit drops to thirty as soon as the road becomes built-up.”
built-up is a quality.
Practised in In the City