3 Syllablesgeometer's, geometers
4 Syllablesaerometers, barometers, bathometers, bolometers, chronometers, clinometers, cyclometers, gasometers, hydrometers, hygrometers, manometers, micrometers, odometers, pedometers, photometers, piezometers, pyrometers, spectrometers, speedometers, tachometers, tonometers
5 Syllablesanemometers, audiometers, dynamometers, electrometers, galvanometers, inclinometers, magnetometers, radiometers, variometers
6 Syllablesalcoholometers, interferometers, potentiometers