The Collaborative International Dictionary of English v.0.48:
Modulate \Mod"u*late\, v. t. [imp. & p. p. Modulated; p. pr. &
vb. n. Modulating.] [L. modulatus, p. p. of modulari to
measure, to modulate, fr. modulus a small measure, meter,
melody, dim. of modus. See Mode.]
1. To form, as sound, to a certain key, or to a certain
2. To vary or inflect in a natural, customary, or musical
manner; as, the organs of speech modulate the voice in
reading or speaking.
Could any person so modulate her voice as to deceive
so many? --Broome.
3. (Electronics) To alter the amplitude, frequency, phase, or
intensity of (the carrier wave of a radio signal) at
intervals, so as to represent information to be conveyed
by the signal; -- a technique used to convey information
by means of radio waves transmitted by one electronic
device and received by another.