資料來源 : Webster's Revised Unabridged Dictionary (1913)

Time \Time\, n.; pl. {Times}. [OE. time, AS. t[=i]ma, akin to
   t[=i]d time, and to Icel. t[=i]mi, Dan. time an hour, Sw.
   timme. [root]58. See {Tide}, n.]
   1. Duration, considered independently of any system of
      measurement or any employment of terms which designate
      limited portions thereof.

            The time wasteth [i. e. passes away] night and day.
                                                  --Chaucer.

            I know of no ideas . . . that have a better claim to
            be accounted simple and original than those of space
            and time.                             --Reid.

   2. A particular period or part of duration, whether past,
      present, or future; a point or portion of duration; as,
      the time was, or has been; the time is, or will be.

            God, who at sundry times and in divers manners spake
            in time past unto the fathers by the prophets.
                                                  --Heb. i. 1.

   3. The period at which any definite event occurred, or person
      lived; age; period; era; as, the Spanish Armada was
      destroyed in the time of Queen Elizabeth; -- often in the
      plural; as, ancient times; modern times.

   4. The duration of one's life; the hours and days which a
      person has at his disposal.

            Believe me, your time is not your own; it belongs to
            God, to religion, to mankind.         --Buckminster.

   5. A proper time; a season; an opportunity.

            There is . . . a time to every purpose. --Eccl. iii.
                                                  1.

            The time of figs was not yet.         --Mark xi. 13.

   6. Hour of travail, delivery, or parturition.

            She was within one month of her time. --Clarendon.

   7. Performance or occurrence of an action or event,
      considered with reference to repetition; addition of a
      number to itself; repetition; as, to double cloth four
      times; four times four, or sixteen.

            Summers three times eight save one.   --Milton.

   8. The present life; existence in this world as contrasted
      with immortal life; definite, as contrasted with infinite,
      duration.

            Till time and sin together cease.     --Keble.

   9. (Gram.) Tense.

   10. (Mus.) The measured duration of sounds; measure; tempo;
       rate of movement; rhythmical division; as, common or
       triple time; the musician keeps good time.

             Some few lines set unto a solemn time. --Beau. &
                                                  Fl.

   Note: Time is often used in the formation of compounds,
         mostly self-explaining; as, time-battered,
         time-beguiling, time-consecrated, time-consuming,
         time-enduring, time-killing, time-sanctioned,
         time-scorner, time-wasting, time-worn, etc.

   {Absolute time}, time irrespective of local standards or
      epochs; as, all spectators see a lunar eclipse at the same
      instant of absolute time.

   {Apparent time}, the time of day reckoned by the sun, or so
      that 12 o'clock at the place is the instant of the transit
      of the sun's center over the meridian.

   {Astronomical time}, mean solar time reckoned by counting the
      hours continuously up to twenty-four from one noon to the
      next.

   {At times}, at distinct intervals of duration; now and then;
      as, at times he reads, at other times he rides.

   {Civil time}, time as reckoned for the purposes of common
      life in distinct periods, as years, months, days, hours,
      etc., the latter, among most modern nations, being divided
      into two series of twelve each, and reckoned, the first
      series from midnight to noon, the second, from noon to
      midnight.

   {Common time} (Mil.), the ordinary time of marching, in which
      ninety steps, each twenty-eight inches in length, are
      taken in one minute.

   {Equation of time}. See under {Equation}, n.

   {In time}.
       (a) In good season; sufficiently early; as, he arrived in
           time to see the exhibition.
       (b) After a considerable space of duration; eventually;
           finally; as, you will in time recover your health and
           strength.

   {Mean time}. See under 4th {Mean}.

   {Quick time} (Mil.), time of marching, in which one hundred
      and twenty steps, each thirty inches in length, are taken
      in one minute.

   {Sidereal time}. See under {Sidereal}.

   {Standard time}, the civil time that has been established by
      law or by general usage over a region or country. In
      England the standard time is Greenwich mean solar time. In
      the United States and Canada four kinds of standard time
      have been adopted by the railroads and accepted by the
      people, viz., Eastern, Central, Mountain, and Pacific
      time, corresponding severally to the mean local times of
      the 75th, 90th, 105th, and 120th meridians west from
      Greenwich, and being therefore five, six, seven, and eight
      hours slower than Greenwich time.

   {Time ball}, a ball arranged to drop from the summit of a
      pole, to indicate true midday time, as at Greenwich
      Observatory, England. --Nichol.

   {Time bargain} (Com.), a contract made for the sale or
      purchase of merchandise, or of stock in the public funds,
      at a certain time in the future.

Mean \Mean\, a. [OE. mene, OF. meiien, F. moyen, fr. L. medianus
   that is in the middle, fr. medius; akin to E. mid. See
   {Mid}.]
   1. Occupying a middle position; middle; being about midway
      between extremes.

            Being of middle age and a mean stature. --Sir. P.
                                                  Sidney.

   2. Intermediate in excellence of any kind.

            According to the fittest style of lofty, mean, or
            lowly.                                --Milton.

   3. (Math.) Average; having an intermediate value between two
      extremes, or between the several successive values of a
      variable quantity during one cycle of variation; as, mean
      distance; mean motion; mean solar day.

   {Mean distance} (of a planet from the sun) (Astron.), the
      average of the distances throughout one revolution of the
      planet, equivalent to the semi-major axis of the orbit.

   {Mean error} (Math. Phys.), the average error of a number of
      observations found by taking the mean value of the
      positive and negative errors without regard to sign.

   {Mean-square error}, or {Error of the mean square} (Math.
      Phys.), the error the square of which is the mean of the
      squares of all the errors; -- called also, especially by
      European writers, {mean error}.

   {Mean line}. (Crystallog.) Same as {Bisectrix}.

   {Mean noon}, noon as determined by mean time.

   {Mean proportional} (between two numbers) (Math.), the square
      root of their product.

   {Mean sun}, a fictitious sun supposed to move uniformly in
      the equator so as to be on the meridian each day at mean
      noon.

   {Mean time}, time as measured by an equable motion, as of a
      perfect clock, or as reckoned on the supposition that all
      the days of the year are of a mean or uniform length, in
      contradistinction from apparent time, or that actually
      indicated by the sun, and from sidereal time, or that
      measured by the stars.

資料來源 : WordNet®

mean time
     n : (astronomy) time based on the motion of the mean sun (an
         imaginary sun moving uniformly along the celestial
         equator) [syn: {mean solar time}]