Searching ground with no known deposit — the highest-risk, highest-reward end of exploration.
Exploration activities conducted in areas with no previous mining or exploration history. Greenfield projects carry higher geological risk but offer potential for major new discoveries. Contrasts with brownfield exploration near existing mines or known deposits.
Greenfield discovery is where the multiples are, and where most capital is lost. It is also what flow-through financing exists to fund, since the tax treatment is designed to push money into genuine exploration.
108 terms have their own page: the definition, why it matters to an investor, where it shows up in practice, and the mistake people make with it.