3 syllables:
chyometer, cometer, mhometer, pneometer, prometer, promettre, vomitar, vomiter

4 syllables:
acometer, airometer, algometer, altometer, arthrometer, astrometer, atmometer, attometer, auxometer, axometer, 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, kilometer, 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

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

6 syllables:
absorptiometer, accelerometer, aesthesiometer, albuminometer, apomecometer, arteriometer, astrophotometer, beckman thermometer, bronchospirometer, candy thermometer, chronothermometer, cubic kilometer, 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

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

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

9 syllables:
radio interferometer

11 syllables:
maximum and minimum thermometer

3 syllables:
polisher, chronicler, moniker, cottager, oliver, omnivore, shoplifter, sonneteer, machmeter, dropkicker, hop-picker, polypore, rotifer, somme river

4 syllables:
depositor, discomfiture, compositor, admonisher, canopic jar

5 syllables:
ovipositor