submicroscopicadj.n.

1843 W. MacGillivray Hist. Molluscous Animals p. xi I have found several species hitherto unknown..and several minute or submicroscopic creatures which could hardly have been expected on our northern shores.

1899 Proc. Amer. Acad. Arts & Sci. 34 387 The presence of submicroscopic cracks or planes of parting..will necessarily give the acid greater surface by which to attack.

1938 S. Chase Tyranny of Words iii. 20 The submicroscopic, which we do not consciously see or feel.

1978 H. McLeave Borderline Case (1979) xiii. 133 A submicroscopic particle that struck and then went to earth.

2001 Independent (Nexis) 23 Nov. 8 Many of the fundamental processes of life are driven by tiny, sub-microscopic engines—assemblies of protein molecules that can exert a mechanical force in a specific direction.

1898 J. A. L. Henderson Petrogr. & Geol. Investig. 30 A few individuals show a decided zonary structure, which is, however, only submicroscopically developed in the majority.

1949 Jrnl. Iron & Steel Inst. 163 270/2 This heat might melt a sub-microscopically thin layer of metal.

2001 B. K. Ridley On Sci. ix. 145 In other words it [sc. Einstein's interpretation of quantum theory] was a statistical theory, the statistics, as usual, cloaking ignorance of the detailed mechanisms operating submicroscopically.