a. Of or pertaining to mode, modulation, module, or modius; as, modular arrangement; modular accent; modular measure. [ 1913 Webster ]

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 portion. [ 1913 Webster ]

2. To vary or inflect in a natural, customary, or musical manner; as, the organs of speech modulate the voice in reading or speaking. [ 1913 Webster ]

Could any person so modulate her voice as to deceive so many? Broome. [ 1913 Webster ]

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. [ WordNet 1.5 ]

v. i. (Mus.) To pass from one key into another. [ 1913 Webster ]

adj. (Electronics) 1. Having either amplitude, intensity, frequency, or phase altered at intervals to represent information to be transmitted; -- of the carrier wave of a radio signal transmitted from one device to another for the purpose of conveying information. Opposite of unmodulated. [ Narrower terms: frequency modulated; amplitude modulated ] [ WordNet 1.5 ]

2. altered in volume as well as tone or pitch. [ WordNet 1.5 ]

n. [ L. modulatio: cf. F. modulation. ] 1. The act of modulating, or the state of being modulated; as, the modulation of the voice. [ 1913 Webster ]

2. Sound modulated; melody. [ R. ] Thomson. [ 1913 Webster ]

3. (Mus.) A change of key, whether transient, or until the music becomes established in the new key; a shifting of the tonality of a piece, so that the harmonies all center upon a new keynote or tonic; the art of transition out of the original key into one nearly related, and so on, it may be, by successive changes, into a key quite remote. There are also sudden and unprepared modulations. [ 1913 Webster ]

4. (Electronics) The alteration of hte amplitude, intensity, frequency, or phase (of the carrier wave of a radio signal) at intervals, so as to represent information to be transmitted. [ WordNet 1.5 ]

n. [ L. ] One who, or that which, modulates. Denham. [ 1913 Webster ]

n. An electronic device that converts electronic signals into sound waves, and sound waves into electronic signals, used to transmit information between computers by the use of ordinary telephone lines; usually called a modem. [ PJC ]

v. t. [ See module, n., Modulate. ] To model; also, to modulate. [ Obs. ] Sandys. Drayton. [ 1913 Webster ]

n. [ F., fr. L. modulus a small measure, dim. of modus. See Mode, and cf. Model, Modulus, Mold a matrix. ] 1. A model or measure. [ 1913 Webster ]

2. (Arch.) The size of some one part, as the diameter of semi-diameter of the base of a shaft, taken as a unit of measure by which the proportions of the other parts of the composition are regulated. Generally, for columns, the semi-diameter is taken, and divided into a certain number of parts, called minutes (see Minute), though often the diameter is taken, and any dimension is said to be so many modules and minutes in height, breadth, or projection. [ 1913 Webster ]

‖n.; pl. Moduli [ L., a small measure. See Module, n. ] (Math., Mech., & Physics) A quantity or coefficient, or constant, which expresses the measure of some specified force, property, or quality, as of elasticity, strength, efficiency, etc.; a parameter. [ 1913 Webster ]

Modulus of a machine, a formula expressing the work which a given machine can perform under the conditions involved in its construction; the relation between the work done upon a machine by the moving power, and that yielded at the working points, either constantly, if its motion be uniform, or in the interval of time which it occupies in passing from any given velocity to the same velocity again, if its motion be variable; -- called also the efficiency of the machine. Mosley. Rankine. --
Modulus of a system of logarithms (Math.), a number by which all the Napierian logarithms must be multiplied to obtain the logarithms in another system. --
Modulus of elasticity. (a) The measure of the elastic force of any substance, expressed by the ratio of a stress on a given unit of the substance to the accompanying distortion, or strain. (b) An expression of the force (usually in terms of the height in feet or weight in pounds of a column of the same body) which would be necessary to elongate a prismatic body of a transverse section equal to a given unit, as a square inch or foot, to double, or to compress it to half, its original length, were that degree of elongation or compression possible, or within the limits of elasticity; -- called also Young's modulus. --
Modulus of rupture, the measure of the force necessary to break a given substance across, as a beam, expressed by eighteen times the load which is required to break a bar of one inch square, supported flatwise at two points one foot apart, and loaded in the middle between the points of support. Rankine. [ 1913 Webster ]