An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

General: To regulate by or adjust to a certain measure or proportion; tone down. Physics: To alter the value of some parameter characterizing a periodic oscillation. → modulation.

From L. modulatus pr.p. of modulari "to regulate, measure off properly," from modulus "small measure," diminutive of modus "measure, manner," → mode.

Degarâhangidan, from degar "other, another," denoting change, variant digar (Mid.Pers. dit, ditikar "the other, the second;" O.Pers. duvitiya- "second," Av. daibitya-, bitya- "second;" Skt. dvitiya- "second," PIE *duitiio- "second") + âhang "melody, pitch, tune, modulation" (ultimately from Proto-Iranian *āhang-, from prefix ā- + *hang-, from PIE base *seng^wh- "to sing, make an incantation;" cf. O.H.G. singan; Ger. singen; Goth. siggwan; Swed. sjunga; O.E. singan "to chant, sing, tell in song;" maybe cognate with Gk. omphe "voice; oracle") + -idan infinitive suffix.

A combination of two or more waves resulting in the production of frequencies not present in the original waves, the new frequencies being usually the sums and differences of integral multiples of the frequencies in the original waves.
A wave which varies in some characteristic in accordance with the variations of a modulating signal. Compare continuous wave. See modulation

Modulated, p.p. of → modulate; → wave.