A more thorough explanation:

A greenfield site is a piece of land that has never been developed before. This means that the land is likely to be uncontaminated and free from any previous construction or industrial use.

Greenfield sites can be used for a variety of purposes, such as building new homes, creating parks or nature reserves, or establishing a new business. When a company acquires a greenfield site for the purpose of starting a new business, it is often referred to as a "greenfield investment".

Examples of greenfield sites include:

• A large field on the outskirts of a city that has never been built on before
• A forested area that has never been logged or cleared
• A piece of land that was previously used for agriculture but has been left fallow for many years

These examples illustrate the definition of a greenfield site because they all describe land that has never been developed or built on before. This means that the land is likely to be in its natural state, with no existing infrastructure or contamination from previous use.