Definition of poor man's diggings in US English:

poor man's diggings

(also poor man's digging)

noun

Australian
Mining
informal
  • Gold-bearing land which can be mined without substantial capital outlay, or on which large-scale commercial mining is not considered profitable, and which is thus available to be mined by individuals.

Origin

Mid 19th century; earliest use found in Bathurst (New South Wales) Free Press.