millimeter(n = noun.quantity) millimetre, mm - a metric unit of length equal to one thousandth of a meter;
is a kind of metric linear unit
is a part of centimeter, centimetre, cm
has parts: micrometer, micron
A lineal measure in the metric system, containing the thousandth part of a meter; equal to .03937 of an inch. See 3d Meter. [1913 Webster]
N length, longitude, span, mileage, distance, line, bar, rule, stripe, streak, spoke, radius, lengthening, prolongation, production, protraction, tension, tensure, extension, line, nail, inch, hand, palm, foot, cubit, yard, ell, fathom, rood, pole, furlong, mile, league, chain, link, arpent, handbreadth, jornada, kos, vara, astronomical unit, AU, light- year, parsec, nanometer, nm, micron, micrometer, millimicron, millimeter, mm, centimeter, cm, meter, kilometer, km, pedometer, perambulator, scale, long, longsome, lengthy, wiredrawn, outstretched, lengthened, sesquipedalian, interminable, no end of, macrocolous, linear, lineal, longitudinal, oblong, as long as my arm, as long as today and tomorrow, unshortened &c (shorten), lengthwise, at length, longitudinally, endlong, along, tandem, in a line, in perspective, from end to end, from stem to stern, from head to foot, from the crown of the head to the sole of the foot, from top to toe, fore and aft.