Definition of "built-up" [built-up]

• Made by fastening several layers or sections one on top of the other: a built-up roof. (adjective)
• Filled with buildings; developed: a built-up neighborhood. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "They are a smart approach in built-up areas, and the space gained by removing the two extra travel lanes (and adding a center turn lane) can be used for bike lanes, pedestrian enhancements, etc.."
• "In the past three years violence has subsided, with suicide bombings on targets in built-up areas becoming rare."
• "The thriving, rich civilizations and cultures of North and South America collapsed under the ravages of imported diseases against which indigenous people had no built-up immunities."