ZERO

I. noun (plural ~s; also ~es) Etymology: French or Italian; French zéro, from Italian ~, from Medieval Latin zephirum, from Arabic ṣifr Date: 1598 1. the arithmetical symbol 0 or Ø denoting the absence of all magnitude or quantity, additive identity , a value of an independent variable that makes a function equal to ~ , see: number 3. a. the point of departure in reckoning, the temperature represented by the ~ mark on a thermometer, the setting or adjustment of the sights of a firearm that causes it to shoot to point of aim at a desired range, an insignificant person or thing ; nonentity , 5. a state of total absence or neutrality, the lowest point ; nadir , something arbitrarily or conveniently designated ~, II. adjective Date: 1810 1. of, relating to, or being a ~, having no magnitude or quantity ; not any , c. having no phonetic manifestation , having no modified inflectional form , 2. limiting vision to 50 feet (15 meters) or less, limited to 165 feet (50.3 meters) or less, III. verb Date: 1913 transitive verb to determine or adjust the ~ of (as a rifle), 2. to concentrate firepower on the exact range of, to bring to bear on the exact range of a target, intransitive verb to adjust fire on a specific target, to close in on or focus attention on an objective