zero

/zear"oh/, n., pl. zeros, zeroes, v., zeroed, zeroing, adj.

n.

1. the figure or symbol 0, which in the Arabic notation for numbers stands for the absence of quantity; cipher.

2. the origin of any kind of measurement; line or point from which all divisions of a scale, as a thermometer, are measured in either a positive or a negative direction.

3. a mathematical value intermediate between positive and negative values.

4. naught; nothing.

5. the lowest point or degree.

6. Ling. the absence of a linguistic element, as a phoneme or morpheme, in a position in which one previously existed or might by analogy be expected to exist, often represented by the symbol Ø: Inflectional endings were reduced to zero. The alternant of the plural morpheme in "sheep" is zero.

7. Ordn. a sight setting for both elevation and windage on any particular range causing a projectile to strike the center of the target on a normal day, under favorable light conditions, with no wind blowing.

8. Math.

a. the identity element of a group in which the operation is addition.

b. (of a function, esp. of a function of a complex variable) a point at which a given function, usually a function of a complex variable, has the value zero; a root.

9. (cap.) a single-engine Japanese fighter plane used in World War II.

v.t.

10. to adjust (an instrument or apparatus) to a zero point or to an arbitrary reading from which all other readings are to be measured.

11. to reduce to zero.

12. Slang. to kill (a congressional bill, appropriation, etc.): The proposed tax increase has been zeroed for the time being.

13. zero in, to aim (a rifle, etc.) at the precise center or range of a target.

14. zero in on,

a. to aim directly at (a target).

b. to direct one's attention to; focus on; concentrate on.

c. to converge on; close in on.

adj.

15. amounting to zero: a zero score.

16. having no measurable quantity or magnitude; not any: zero economic growth.

17. Ling. noting a hypothetical morphological element that is posited as existing by analogy with a regular pattern of inflection or derivation in a language, but is not represented by any sequence of phonological elements: the zero allomorph of "-ed" in "cut"; "Deer" has a zero plural.

18. Meteorol.

a. (of an atmospheric ceiling) pertaining to or limiting vertical visibility to 50 ft. (15.2 m) or less.

b. of, pertaining to, or limiting horizontal visibility to 165 ft. (50.3 m) or less.

19. Finance. zero-coupon.

20. being or pertaining to the precise time, as a specific hour or second, when something must or does happen, as the explosion of a nuclear weapon: in an underground shelter at zero second.

[1595-1605; < It < ML zephirum < Ar sifr CIPHER]

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in full Mitsubishi A6M Zero

Japanese fighter aircraft of World War II. A single-seat, low-wing monoplane made by Mitsubishi, it was introduced in 1940, the 2,600th anniversary of the crowning of Japan's legendary first emperor, Jimmu, and named for the "zero-year" celebration.

It had a top speed of 350 mph (565 kph) at nearly 20,000 ft (6,000 m). When it first appeared, it could outmaneuver every plane it encountered; Allied fighters could not defeat it until 1943. Many Zeros became kamikaze craft in the war's closing months.

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▪ Japanese aircraft

also called  Mitsubishi A6M or Navy Type 0 

      fighter aircraft, a single-seat, low-wing monoplane used with great effect by the Japanese during World War II. Designed by Horikoshi Jiro, it was the first carrier-based fighter capable of besting its land-based opponents. It was designed to specifications written in 1937, was first tested in 1939, and was placed in production and in operation in China in 1940. Although Allied forces code-named the aircraft “Zeke,” it was generally known as the Zero, a term derived from one of its Japanese names—Reisen Kanjikisen (Type Zero Carrier-based Fighter Airplane), abbreviated Reisen. The year its production began, 1940, was the 2,600th anniversary of the ascension to the throne of Japan's legendary first emperor, Jimmu, hence the “zero” designation.

      The Zero was made by Mitsubishi (Mitsubishi Group) Heavy Industries and was first powered by a Nakajima Sakae radial air-cooled engine of 14 cylinders (two staggered rows of seven) that developed 1,020 horsepower. Later it used a 1,130-horsepower engine to turn its three-blade constant-speed propeller. Its top speed was 350 miles per hour (565 km/h) at nearly 20,000 feet (6,100 m), and it was armed with two 7.7-millimetre machine guns and two 20-millimetre cannons in its wings; it could carry two 132-pound (59.9-kilogram) bombs under the wings.

      When it first appeared, the Zero could outmaneuver every airplane it encountered. Moreover, its 156-gallon (591-litre) internal fuel tank was augmented with a 94-gallon external tank that could be dropped when empty, thus enabling the Zero to fly far beyond its expected range. The Allies did not field fighters that could defeat it in aerial combat until 1943. Many Zeros were converted to kamikaze craft in the closing months of the war. In all, nearly 10,430 of them were built.

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