2 syllables:
-meter, -metre, -seater, beater, beat her, beter, bleater, cheater, cretor, deater, deeter, detre, dieter, eater, eat her, feater, fetor, fleeter, foetor, freeter, geeter, greeter, greet her, heater, heeter, jeeter, jeter, keator, keeter, keiter, keytar, liter, litre, meeter, meet her, meter, metre, mitter, neater, peeter, peter, pieter, pleater, praeter, praeter-, praetor, preter, preter-, pretor, rieter, saeter, schleeter, seater, sheeter, skeeter, sleeter, sliter, spitir, streater, streator, streeter, strieter, sweeter, teater, teeter, teter, treater, treat her, tweeter, vietor, yeater, zetor

3 syllables:
chyometer, cometer, mhometer, pneometer, prometer, promettre, vomitar, vomiter, aliter, all-seater, ammeter, ant-eater, anteater, arreter, bee-eater, beefeater, bee eater, bhangmeter, blue peter, browbeater, champetre, coal-meter, competere, completar, completer, complete her, crabeater, croweater, defeater, demeter, demetre, depleter, discreeter, drumbeater, e-meter, egg-beater, eggbeater, elfmeter, entreater, figeater, fire-eater, fisheater, fluxmeter, gas heater, gas meter, gnateater, gold-beater, goldbeater, leadbeater, light meter, luxmeter, maltreater, man-eater, maneater, meateater, molitor, oil heater, oometer, physeter, preheater, propraetor, propretor, pyoureter, rainmeter, receiptor, reheater, repeater, retreater, rug beater, saint peter, saltpetre, seedeater, sin-eater, snow eater, space heater, square meter, st peter, tenthmetre, toad-eater, toadeater, torquemeter, two-seater, ureter, vanmeter, vanmetre, wattmeter, wife-beater, windcheater, world-beater, worldbeater

4 syllables:
acometer, airometer, algometer, altometer, arthrometer, astrometer, atmometer, attometer, auxometer, axometer, barometer, bathometer, bdellometer, biometer, bogometer, breathometer, capnometer, ceilometer, chartometer, chondrometer, chromometer, chronometer, clapometer, comptometer, conchometer, coolometer, cratometer, cryptometer, cymometer, cyrtometer, cytometer, dendrometer, disdrometer, drosometer, drunkometer, durometer, echometer, femtometer, fluorometer, flushometer, focometer, geometer, glaucometer, gleucometer, glucometer, graphometer, haemometer, haptometer, hectometer, hektometer, hodometer, horometer, hydrometer, hygrometer, hypsometer, iometer, lactometer, lensometer, mecometer, meldometer, metrometer, micrometer, monometer, nephometer, nitrometer, octometer, odometer, ombrometer, oncometer, ondometer, optometer, orometer, osmometer, pachometer, pedometer, phacometer, phonometer, phorometer, photometer, phthongometer, picometer, pitchometer, plastometer, platometer, pneumometer, potometer, psophometer, psychometer, psychrometer, pulmometer, pycnometer, pyknometer, pyrometer, quantometer, reometer, rheometer, riometer, sclerometer, scotometer, seismometer, sismometer, slidometer, spectrometer, speedometer, spherometer, sphigmometer, sphygmometer, spirometer, stactometer, stagmometer, staktometer, stethometer, strainometer, stylometer, swingometer, tachometer, tactometer, termometer, thermometer, tintometer, tocometer, trechometer, trekometer, tribometer, trochometer, tromometer, tropometer, udometer, urometer, vibrometer, viscometer, worldometer, xylometer, zymometer, aerometer, amperemeter, antimeter, attolitre, attometre, avometer, barkometer, bathymeter, bolometer, brontometer, calcimeter, campimeter, carpet beater, centiliter, centilitre, centimeter, centimetre, chlorometer, clinometer, common meter, coulometer, cryometer, cubic meter, cyclometer, dasymeter, decametre, deciliter, decilitre, decimeter, decimetre, decremeter, dekametre, densimeter, diametre, dosemeter, ergometer, exalitre, exametre, expositor, fathometer, femtometre, fluorimeter, focimeter, gasometer, gigalitre, gigameter, gigametre, gravimeter, great anteater, halometer, hannah jeter, hazemeter, hectolitre, hectometre, holometer, honey-eater, honeyeater, honey eater, hypermeter, joulemeter, kilolitre, kilometre, klinometer, konimeter, labimeter, lanameter, logometer, lotos-eater, lotus-eater, lotus eater, macrometer, manometer, megameter, megametre, mekometer, mentimeter, micrometre, mililiter, milliammeter, milliliter, millilitre, millimeter, millimetre, milometer, multimeter, nanolitre, nanometer, nanometre, neotheater, newton-meter, newton-metre, nilometer, nonsecretor, oenometer, ohmmeter, overeater, oximeter, pachymeter, pantometer, passometer, pelvimeter, petalitre, petameter, petametre, phall-o-meter, picolitre, picometre, planimeter, planometer, platymeter, plessimeter, pleximeter, postage meter, pulsimeter, pulsometer, qualimeter, salimeter, salometer, sillometer, similiter, solar heater, sonometer, stadimeter, stenometer, sulfameter, superheater, tachymeter, tasimeter, taximeter, telemeter, tensimeter, teralitre, terameter, terametre, tetrameter, tonometer, trick-or-treater, turgometer, vacuometer, vinometer, voltameter, water heater, water meter, yoctolitre, yoctometre, yottalitre, yottameter, yottametre, zentimeter, zeptolitre, zeptometre, zettalitre, zettameter, zettametre

5 syllables:
aberrometer, acetometer, acidometer, adaptometer, air thermometer, albedometer, alcohometer, aleurometer, ametrometer, amperometer, amylometer, anemometer, angulometer, anthracometer, apertometer, araeometer, areometer, arithmometer, astigmometer, atmidometer, audiometer, azotometer, butyrometer, carbonometer, cardiometer, cathetometer, chromatometer, chromoptometer, craniometer, declinometer, deflectometer, densitometer, diagometer, diffractometer, dilatometer, dioptometer, dynamometer, eikonometer, elaeometer, elaiometer, elatrometer, electrometer, ellipsometer, endosmometer, eriometer, eudiometer, extensometer, fluviometer, galactometer, gas thermometer, glycosometer, goniometer, gradiometer, gravitometer, haemadrometer, haematometer, harmonometer, heliometer, hemadrometer, hyetometer, iconometer, inclinnometer, inclinometer, inductometer, infiltrometer, inspirometer, katharometer, kathetometer, keratometer, labidometer, magnetometer, mass spectrometer, meat thermometer, methanometer, micronometer, mileometer, nauropometer, nephelometer, odynometer, oleometer, olfactometer, ophthalmometer, opisometer, opsiometer, orchidometer, oscillometer, ozonometer, penetrometer, piezometer, pluviometer, pneumatometer, pupillometer, pupilometer, pyrgeometer, rachiometer, radiometer, reflectometer, reflexometer, refractometer, respirometer, rhythmometer, roentgenometer, saccharometer, salinometer, scatterometer, scoliometer, sensitometer, sociometer, stadiometer, stalagmometer, strabismometer, tacheometer, taseometer, tellurometer, tensiometer, thoracometer, tithonometer, torsiometer, urinometer, variometer, weatherometer, acetimeter, acidimeter, actinometer, alcalimeter, algesimeter, anthropometer, auxanometer, banded anteater, cephalometer, co-oximeter, coercimeter, cyanometer, ductilimeter, elastometer, electric heater, exposure meter, extensimeter, galvanometer, geodimeter, giant anteater, globulimeter, gram-centimeter, gravity meter, indigometer, intoximeter, kerosene heater, kilogram-meter, kilogrammetre, lesser anteater, microammeter, myrialitre, myriameter, myriametre, new world anteater, opacimeter, opium-eater, penetrameter, photogrammeter, pluviameter, pneumonometer, profilometer, pyranometer, scintillometer, silky anteater, spiny anteater, stereometer, submillimeter, transmissometer, turbidimeter, ureameter, velocimeter, viscosimeter

6 syllables:
absorptiometer, accelerometer, aesthesiometer, albuminometer, apomecometer, arteriometer, astrophotometer, beckman thermometer, bronchospirometer, candy thermometer, chronothermometer, cytophotometer, decelerometer, diaphanometer, diathermometer, diffusiometer, ebulliometer, effusiometer, elaterometer, esthesiometer, eurobarometer, evaporometer, exophthalmometer, gastrotonometer, geothermometer, haemacytometer, haematachometer, haemochromometer, haemocytometer, hemacytometer, hemadromometer, hemocytometer, hydrobarometer, interferometer, intervalometer, katathermometer, kinesiometer, meteorometer, microchronometer, microphotometer, microseismometer, nephelodometer, oven thermometer, pantochronometer, parallelometer, parturiometer, perineometer, photographometer, platinum thermometer, potentiometer, pyrheliometer, pyrophotometer, spectrobolometer, spectrofluorometer, spectrophotometer, sphygmotonometer, telethermometer, thermobarometer, thermohydrometer, ultramicrometer, volumenometer, albuminimeter, alcoholometer, baromacrometer, carmelita jeter, cubic centimeter, cubic millimeter, dynactinometer, haematinometer, haemomanometer, lactodensimeter, microbolometer, micromillimeter, micromillimetre, spectrofluorimeter, sphygmomanometer, thermogravimeter

7 syllables:
baraesthesiometer, baresthesiometer, barocyclonometer, cardiotachometer, centigrade thermometer, clinical thermometer, electric thermometer, erythrocytometer, fahrenheit thermometer, gnathodynamometer, hemadynamometer, hemoglobinometer, hydrodynamometer, kinesthesiometer, lactobutyrometer, mercury barometer, mercury thermometer, microdensitometer, myodynamometer, oligochronometer, photoheliometer, pupillostatometer, radiomicrometer, resistance thermometer, reversing thermometer, spectroradiometer, thermesthesiometer, thermoelectrometer, tocodynamometer, vernier micrometer, volta-electrometer, psychogalvanometer

8 syllables:
electro-dynamometer, electrodynamometer, microspectrophotometer, ophthalmodynamometer, radiogoniometer, telehydrobarometer

9 syllables:
radio interferometer

11 syllables:
maximum and minimum thermometer

3 syllables:
brontosaur, sloganeer, hosteller, monitor, hollander, godmother, nodular, polymer, proposer, jocular, cockchafer, sodbuster, popular, cocklebur, modeler, hogchoker, goddaughter, commodore, colander, columnar, alcazar, oliver, blockbuster, pompadour, bolivar, gospeler, modeller, monomer, commissar, globular, almoner, onager, stomacher, gobbler, gossamer, commoner, nonpolar, pothunter, conifer, nothosaur, gossiper, slopseller, common murre, cottager, gospeller, groveller, holloware, ocular, promiser, promisor, quadrature, swashbuckler, troposphere, wobbler

4 syllables:
biographer, astronomer, unpopular, bilocular, demographer, photographer, pornographer, binocular, philosopher, astrologer, subocular, geographer, reconciler, siphonophore, assam rubber, black hollander, compositor, copolymer, cosmographer, dock-walloper, ethnographer, heart monitor, horologer, involucre, lithographer, pisanosaur, typographer, wicket-keeper

5 syllables:
interlocutor, lexicographer, choreographer, ovipositor, vinyl polymer, bibliographer, oceanographer, press photographer, radiographer, simon bolivar, divinyl ether, virginia creeper

6 syllables:
autobiographer, cinematographer, african monitor, cardiac monitor, historiographer, silicone polymer

7 syllables:
political commissar

9 syllables:
electronic fetal monitor