| 释义 | 
		ze·ro I. \ˈzē(ˌ)rō, ˈzi(-\ noun (plural zeros also zeroes) Etymology: French or Italian; French zéro, from Italian zero, from Medieval Latin zephirum, from Arabic ṣifr empty, cipher, zero 1.   a.  : the arithmetical symbol 0 or Ø denoting the absence of all magnitude or quantity : cipher, naught  b.  : a number or element that leaves unchanged any number or element to which it is added; specifically  : the number between the set of all negative numbers and the set of all positive numbers — see number table  c.  : a value of the independent variable of a function that makes it equal to zero   < +2 and -2 are zeros of f(x)=x2-4 > 2.   a.    (1)  : the point of departure in reckoning; specifically  : the point from which the graduation of a scale (as of a thermometer) commences   (2)  : the temperature represented by the zero mark on a thermometer  b.  : zero hour 1  c.    (1)  : the basic setting of the rear sight of a firearm that compensates for inaccuracies of weapon and of firing habits and for elevation required at a given range and that causes the firearm to hit where aimed under normal conditions   (2)  : the adjustment (as for elevation, windage) required for a gun or other device to achieve accuracy under specific operating conditions 3.  : a person or thing that has no importance, influence, or independent existence : nonentity, nobody, nothing, cipher 4.   a.    (1)  : a state or condition of total absence or of neutrality between opposites : nothing, naught    < a face that registered zero no matter what happened >    < the two eyewitnesses for the State added up to zero, for the defense made mincemeat of their testimony — Ross Colin >    < reduce the mortality rate to zero >    < hold the reversible reaction of the chemical to zero >   (2)  : absence of an overt linguistic feature when this absence is itself significant because of the presence of such a feature at corresponding points in the language    < some vowel which earlier followed the final consonant but which was later reduced to zero — R.A.Hall b. 1911 >  b.  : the lowest point   < his spirits fell to zero — Margaret Kennedy > 5.  : something arbitrarily or conveniently designated zero: as  a.  : the lowest in order or class   < a speech so bad it rated a zero >  b.  : the space numbered 0 on a roulette wheel II. adjective 1.  : of, relating to, or being a zero: as  a.  : forming a fixed point of departure in reckoning   < set the gauge back to the zero mark >   < time zones extending from the zero meridian >   < used the founding date as the zero year of its era >  b.  : having no magnitude or quantity or being intermediate between positive and negative magnitudes or quantities : not any   < zero velocity >   < zero gravity >   < zero angle >   < zero lift >   < zero toe-in >   < zero inches >   < zero mass >   : nil   < chances of making up the lost time were zero >  c.    (1)  : absent, lacking    < the zero modification in the past of cut in comparison with loved, sang >   (2)  : having no modified inflectional form : unmodified    < the noun fish has a zero plural fish as well as a regular plural fishes >  d.    (1)  : belonging to or being a group or class arbitrarily or conveniently designated zero   (2)  : of, relating to, or being a logical class having no members : null, empty    < the zero denotation of the term unicorn >    < zero class > 2.   a. of an atmospheric ceiling  : limiting vision to 50 feet or less  b. of horizontal visibility  : limited to 165 feet or less III. verb (-ed/-ing/-es) transitive verb 1.  : to adjust (as by firing under test conditions) the zero of — often used with in  < zeroed in his rifle at 100 yards > 2.  : to adjust (an instrument or device) to zero value or into synchronism 3.   a.  : to concentrate firepower (as of mortar or artillery) on the exact range of — usually used with in   < it must operate from fixed bases which can be zeroed in by the enemy — Carl Spaatz >  b.  : to bring to bear on the exact range of a target : train — usually used with in   < artillery and mortars were zeroed in on all crossroads and avenues of approach — S.J.Tobin > 4.  : to reduce to zero intransitive verb 1.  : to adjust fire (as of mortars or artillery) on a specific target — usually used with in   < an enemy battery that zeroed in on the crossroad > 2.  : to move near to or focus attention on a person or thing as if on a target : close — usually used with in  < bird-dogs zeroing in on coveys of hidden quail — J.N.Leonard >  < congressional opponents who zeroed in on the bill > |