Adjective
submillimeter (not comparable)
(sciences) Less than a millimeter in size
It now resides in the National Air and Space Museum in Washington, DC. citation Radio and submillimeter telescopes use much larger dishes or antennae, which do not have to be made as precisely as the mirrors used in optical telescopes. Source: Internet
By 1700 its length had been measured with submillimeter accuracy at several cities in Europe. Source: Internet
The BLITS allows millimeter and submillimeter accuracy SLR measurements, as its "target error" (uncertainty of reflection center relative to its center of mass) is less than 0.1 mm. Source: Internet