modulation

Etymology

From Late Middle English modulacion, modulacioun (“act of making music or singing; harmony; melody, song”), from Middle French modulation (modern French modulation), and directly from its etymon Latin modulātiō (“regular or rhythmical measure, modulation; inflection of tone; (architecture) calculation of measurements from a standard unit; (Late Latin) act of making music or singing; melody, song”), from modulātus (“modulated”) + -iō (suffix forming abstract nouns from verbs). Modulātus is a perfect participle of modulor (“to beat time; to make music or sing; to measure; etc.”), from modulus (“rhythmical measure, interval; rhythm; small interval or measure, etc.”) + -or (suffix forming certain inflections of verbs); and modulus is from modus (“measure; method; etc.”) (ultimately from Proto-Indo-European *med- (“to measure; etc.”)) + -ulus (diminutive suffix). By surface analysis, modulat(e) + -ion (suffix denoting an action or process, or its result).