1.  vernier(n = noun.person) paul vernier - French mathematician who described the vernier scale (1580-1637);
is a kind of mathematician

2.  vernier(n = noun.artifact) vernier scale - a small movable scale that slides along a main scale; the small scale is calibrated to indicate fractional divisions of the main scale;
is a kind of scale

   A short scale made to slide along the divisions of a graduated instrument, as the limb of a sextant, or the scale of a barometer, for indicating parts of divisions. It is so graduated that a certain convenient number of its divisions are just equal to a certain number, either one less or one more, of the divisions of the instrument, so that parts of a division are determined by observing what line on the vernier coincides with a line on the instrument. [1913 Webster]

vernier, n. a small movable graduated scale for obtaining fractional parts of subdivisions on a fixed main scale of a barometer, sextant, etc.

Idiom:
vernier engine an auxiliary engine for slight changes in the motion of a space rocket etc.

Etymology:
P. Vernier, Fr. mathematician d. 1637

N  littleness, smallness, exiguity, inextension, parvitude, parvity, duodecimo, Elzevir edition, epitome, microcosm, rudiment, vanishing point, thinness, dwarf, pygmy, pigmy, Liliputian, chit, pigwidgeon, urchin, elf, atomy, dandiprat, doll, puppet, Tom Thumb, Hop-o'-my-thumb, manikin, mannikin, homunculus, dapperling, cock-sparrow, animalcule, monad, mite, insect, emmet, fly, midge, gnat, shrimp, minnow, worm, maggot, entozoon, bacteria, infusoria, microzoa, phytozoaria, microbe, grub, tit, tomtit, runt, mouse, small fry, millet seed, mustard seed, barleycorn, pebble, grain of sand, molehill, button, bubble, point, atom, fragment, powder, point of a pin, mathematical point, minutiae, micrometer, vernier, scale, microphotography, photomicrography, micrography, photomicrograph, microphotograph, microscopy, microscope (optical instruments), little, small, minute, diminutive, microscopic, microzoal, inconsiderable, exiguous, puny, tiny, wee, petty, minikin, miniature, pygmy, pigmy, elfin, undersized, dwarf, dwarfed, dwarfish, spare, stunted, limited, cramp, cramped, pollard, Liliputian, dapper, pocket, portative, portable, duodecimo, dumpy, squat, short, impalpable, intangible, evanescent, imperceptible, invisible, inappreciable, insignificant, inconsiderable, trivial, infinitesimal, homoeopathic, atomic, subatomic, corpuscular, molecular, rudimentary, rudimental, embryonic, vestigial, weazen, scant, scraggy, scrubby, thin, granular, shrunk, brevipennate, in a small compass, in a nutshell, on a small scale, minutely, microscopically.

N  measurement, admeasurement, mensuration, survey, valuation, appraisement, assessment, assize, estimate, estimation, dead reckoning, reckoning, gauging, horse power, metrology, weights and measures, compound arithmetic, measure, yard measure, standard, rule, foot rule, compass, calipers, gage, gauge, meter, line, rod, check, dividers, velo, flood mark, high water mark, Plimsoll line, index, scale, graduation, graduated scale, nonius, vernier, bathometer, galvanometer, heliometer, interferometer, odometer, ombrometer, pantometer, pluviometer, pneumatometer, pneumometer, radiometer, refractometer, respirometer, rheometer, spirometer, telemeter, udometer, vacuometer, variometer, viameter, thermometer, thermistor (heat) &c, barometer (air), anemometer (wind), dynamometer, goniometer, (angle) 244 meter, landmark, balance, scale, marigraph, pneumatograph, stethograph, rain gauge, rain gage, voltmeter (volts), ammeter (amps), spectrophotometer (light absorbance), mass spectrophotometer (molecular mass), geiger counter, scintillation counter (radioactivity), pycnometer (liquid density), graduated cylinder, volumetric flask (volume), radar gun (velocity), radar (distance), side-looking radar, (shape, topography), sonar (depth in water), light meter (light intensity), clock, watch, stopwatch, chronometer (time), anemometer (wind velocity), densitometer (color intensity), measurability, computability, determinability, coordinates, ordinate and abscissa, polar coordinates, latitude and longitude, declination and right ascension, altitude and azimuth, geometry, stereometry, hypsometry, metage, surveying, land surveying, geodesy, geodetics, geodesia, orthometry, altimetry, cadastre, astrolabe, armillary sphere, land surveyor, geometer, measuring, metric, metrical, measurable, perceptible, noticeable, detectable, appreciable, ponderable, determinable, fathomable, geodetical, topographic, topographical, cartographic, cartographical.

paul vernier, vernier caliper, vernier micrometer, vernier scale