submicroscopic

sub mi cro scop ic |ˌsəbmīkrəˈskäpik ˌsəbˌmaɪkrəˈskɑpɪk | ▶adjective too small to be seen by an ordinary light microscope.

submicroscopic

sub |micro |scop ¦ic |ˌsʌbmʌɪkrəˈskɒpɪk | ▶adjective too small to be seen by an ordinary light microscope.