1. Abandoned or underused industrial or commercial properties where expansion or redevelopment is complicated by environmental contamination.
Usage: Usually plural; used in urban planning and environmental policy contexts; Often contrasted with greenfields (undeveloped land)

Examples

• The city launched a program to clean up brownfields and convert them into parks and housing.
• Developers are increasingly interested in brownfields redevelopment as a sustainable alternative to sprawl.
• Many brownfields in the industrial district contain soil contaminated with heavy metals.
• Federal grants help municipalities remediate brownfields and prepare them for new uses.
• The old factory was classified as a brownfield due to previous chemical spills.
• Brownfields redevelopment can revitalize neighborhoods while reducing pressure on undeveloped land.