con·stant /ˈkɑn(t)stənt/
 常數,恆量(a.)不變的,一定的,時常的


 constant
 常數


 constant
 常數


 Con·stant a.
 1. Firm; solid; fixed; immovable; -- opposed to fluid. [Obs.]
    If . . . you mix them, you may turn these two fluid liquors into a constant body.   --Boyle.
 2. Not liable, or given, to change; permanent; regular; continuous; continually recurring; steadfast; faithful; not fickle.  Opposite of changeable and variable.
    Both loving one fair maid, they yet remained constant friends.   --Sir P. Sidney.
    I am constant to my purposes.   --Shak.
    His gifts, his constant courtship, nothing gained.   --Dryden.
    Onward the constant current sweeps.   --Longfellow.
 3. Math. & Physics Remaining unchanged or invariable, as a quantity, force, law, etc.
 4. Consistent; logical. [Obs.]
 Syn: -- Fixed; steadfast; unchanging; permanent; unalterable; immutable; invariable; perpetual; continual; resolute; firm; unshaken; determined.
 Usage: -- Constant, Continual, Perpetual. These words are sometimes used in an absolute and sometimes in a qualified sense. Constant denotes, in its absolute sense, unchangeably fixed; as, a constant mind or purpose. In its qualified sense, it marks something as a “standing” fact or occurence; as, liable to constant interruptions; constantly called for. Continual, in its absolute sense, coincides with continuous. See Continuous. In its qualified sense, it describes a thing as occuring in steady and rapid succession; as, a round of continual calls; continually changing. Perpetual denotes, in its absolute sense, what literally never ceases or comes to an end; as, perpetual motion. In its qualified sense, it is used hyperbolically, and denotes that which rarely ceases; as, perpetual disturbance; perpetual noise; perpetual intermeddling.


 Con·stant, n.
 1. That which is not subject to change; that which is invariable.
 2. Math. A quantity that does not change its value; -- used in countradistinction to variable.
 3. Astron. A number whose value, when ascertained (as by observation) and substituted in a general mathematical formula expressing an astronomical law, completely determines that law and enables predictions to be made of its effect in particular cases.
 4.  Physics A number expressing some property or condition of a substance or of an instrument of precision; as, the dielectric constant of quartz; the collimation constant of a transit instrument.
 Aberration constant, or  Constant of aberration Astron., a number which by substitution in the general formula for aberration enables a prediction to be made of the effect of aberration on a star anywhere situated. Its value is 20˝.47.
 Absolute constant Math., one whose value is absolutely the same under all circumstances, as the number 10, or any numeral.
 Arbitrary constant, an undetermined constant in a differential equation having the same value during all changes in the values of the variables.
 Gravitation constant Physics, the acceleration per unit of time produced by the attraction of a unit of mass at unit distance. When this is known the acceleration produced at any distance can be calculated.
 Solar constant Astron., the quantity of heat received by the earth from the sun in a unit of time. It is, on the C. G. S. system, 0.0417 small calories per square centimeter per second. --Young.
 Constant of integration Math., an undetermined constant added to every result of integration.

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 constant
      adj 1: persistent in occurrence and unvarying in nature;
             "maintained a constant temperature"; "a constant
             beat"; "principles of unvarying validity"; "a steady
             breeze" [syn: changeless, invariant, steady, unvarying]
      2: continually recurring or continuing without interruption;
         "constant repetition of the exercise"; "constant chatter
         of monkeys"
      3: steadfast in purpose or devotion or affection; "a man
         constant in adherence to his ideals"; "a constant lover";
         "constant as the northern star" [ant: inconstant]
      4: uninterrupted in time and indefinitely long continuing; "the
         ceaseless thunder of surf"; "in constant pain"; "night and
         day we live with the incessant noise of the city"; "the
         never-ending search for happiness"; "the perpetual
         struggle to maintain standards in a democracy"; "man's
         unceasing warfare with drought and isolation";
         "unremitting demands of hunger" [syn: ceaseless, incessant,
          never-ending, perpetual, unceasing, unremitting]
      n 1: a quantity that does not vary [syn: constant quantity]
      2: a number representing a quantity assumed to have a fixed
         value in a specified mathematical context; "the velocity
         of light is a constant"