A "brownfield" refers to a previously developed piece of land that is not currently in use and may be contaminated or polluted. These sites often result from industrial or commercial activities, such as factories or gas stations, and can pose environmental challenges. Redeveloping brownfields can help revitalize communities and reduce urban sprawl. Cleaning up and repurposing brownfields can lead to economic growth and improved public health. Various government programs and initiatives, such as the EPA's Brownfields Program, provide funding and support for the assessment and remediation of these sites, encouraging sustainable development and environmental restoration.