Greenfield

n. piece of land or property that is undeveloped

adj. undeveloped in the past (usually of a site)

Greenfield land is a term used to describe a piece of undeveloped land, either currently used for agriculture or just left to nature. In contrast, brownfield land is an area that has previously been developed, such as a paved lot or the site of a demolished building.
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n. พื้นที่สีเขียว