3 syllables:
moniter, sonneter

4 syllables:
admonitor, al-monitor, markmonitor, recognitor

5 syllables:
anti-monitor, multi-monitor

3 syllables:
brontosaur, sloganeer, hosteller, 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, onager, almoner, 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, atmometer, picometer, spectrometer, cryometer, psychrometer, tachometer, spherometer, manometer, astronomer, algometer, hodometer, unpopular, decametre, bilocular, demographer, photographer, pornographer, binocular, clinometer, bolometer, philosopher, kilometer, astrologer, speedometer, subocular, thermometer, geographer, reconciler, odometer, siphonophore, hygrometer, chronometer, micrometer, hydrometer, assam rubber, black hollander, compositor, copolymer, cosmographer, dock-walloper, ethnographer, femtometer, geometer, hectometer, horologer, involucre, lithographer, pedometer, pisanosaur, pyrometer, sclerometer, tintometer, typographer, viscometer

5 syllables:
interlocutor, lexicographer, gas thermometer, salinometer, densitometer, myriameter, choreographer, piezometer, variometer, ovipositor, dynamometer, anemometer, katharometer, mass spectrometer, audiometer, mileometer, vinyl polymer, goniometer, galvanometer, sensitometer, inclinometer, actinometer, declinometer, tacheometer, magnetometer, air thermometer, bibliographer, craniometer, electrometer, eudiometer, meat thermometer, oceanographer, press photographer, radiographer, radiometer, refractometer, simon bolivar

6 syllables:
interferometer, autobiographer, accelerometer, cinematographer, sphygmomanometer, evaporometer, telethermometer, beckman thermometer, candy thermometer, cubic kilometer, historiographer, oven thermometer, platinum thermometer, potentiometer, silicone polymer, thermohydrometer

7 syllables:
clinical thermometer, resistance thermometer, radiomicrometer, centigrade thermometer, electric thermometer, fahrenheit thermometer, mercury thermometer, political commissar, reversing thermometer, vernier micrometer

8 syllables:
electrodynamometer

9 syllables:
radio interferometer

11 syllables:
maximum and minimum thermometer