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:
aliter, all-seater, 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:
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, kilometer, 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:
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:
albuminimeter, alcoholometer, baromacrometer, carmelita jeter, cubic centimeter, cubic millimeter, dynactinometer, haematinometer, haemomanometer, lactodensimeter, microbolometer, micromillimeter, micromillimetre, spectrofluorimeter, sphygmomanometer, thermogravimeter

7 syllables:
psychogalvanometer

3 syllables:
madrepore, bandleader

4 syllables:
dekaliter