a site, either derelict or holding very old buildings, which could be redeveloped for new uses.

an inner-city derelict site which can be cleared and reused for new industry.

a piece of land that has been used and abandoned, and is now awaiting some new use 

Lands on which industrial or commercial activity took place in the past. They may be vacant, underused or abandoned. The soil and water may or may not be impacted by contaminants as a result of past practices and uses.

[federal] Property with contamination which complicates its redevelopment, reuse or expansion. The U.S. Environmental Protection Agency’s Brownfields Initiative is designed to empower states, communit [..]

A site that has previously been built on or used but has now ceased. This term may include disused buildings which could be reused or vacant or derelict land which may be cleared.

 A piece of ex-industrial or ex-commercial land that is abandoned or underused, but which can be considered as a potential site for redevelopment.