IPA: /ˌmaɪkrəˈskɒpɪkəl/
KK: /maɪkrəˈskɒpɪkəl/
Relating to very small things that can only be seen with a microscope.
The scientist studied the microscopical details of the cell structure.
Microscopical → It is formed from "micro-" (from Greek "mikros", meaning small) and "scopium" (from Greek "skopein", meaning to look or examine) and the suffix "-al" (meaning pertaining to). The word "microscopical" refers to something that pertains to looking at small things, typically those that cannot be seen with the naked eye.
Think of 'small' ('micro-') and 'looking' ('skopein') to remember that 'microscopical' means related to examining tiny things.