Definition of "microscopical"

microscopical

adjective
comparative more microscopical, superlative most microscopical
1. Pertaining to the microscope; achieved by means of a microscope.
2. (now rare) Only visible by means of a microscope; very small, microscopic.
  Quotations
  I have observed in green Wood all those long Microscopical pores which appear in Charcoal perfectly empty of any thing but Air.
  1665, Robert Hooke, Micrographia, section XVIII