资料来源 : pyDict

常数,恒量不变的,一定的,时常的

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Constant \Con"stant\, n.
   1. (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.

   2. (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[sec].47.

   {Constant of integration} (Math.), an undetermined constant
      added to every result of integration.

   {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 \Con"stant\, a. [L. onstans, -antis, p. pr. of constare
   to stand firm, to be consistent; con- + stare to stand: cf.
   F. constant. See {Stand} and cf. {Cost}, v. t.]
   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.

            Both loving one fair maid, they yet remained
            constant friends.                     --Sir P.
                                                  Sidney.

            I am constant to my purposes.         --Shak.

            His gifts, his constant ourtship, 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.] --Shak.

   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.

Constant \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}.

   {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.

资料来源 : WordNet®

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}]

constant
     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"