noun pl. zeros -·ros or zeroes -·roes

1. the symbol or numeral 0, representing the complete absence of any quantity or magnitude
2. the point, marked 0, from which positive or negative quantities are reckoned on a graduated scale, as on a thermometer; specif.,
   1. on a centigrade thermometer, the freezing point of water
   2. on a Fahrenheit thermometer, a point 32° below the freezing point of water
3. a temperature that causes a thermometer to register zero
4. the point intermediate between positive and negative quantities
5. nothing
6. the lowest point his chances of success sank to zero
7. Gunnery a sight setting for a range, allowing for both elevation and windage

Etymology: Fr zéro < It zero < Ar ṣifr, cipher

adjective

1. of or at zero
2. without measurable value
3. Informal not any; no a snack having zero cholesterol
4. Aeron.
   1. designating or of a ceiling that is at or near the ground, specif. one at a height of fifty feet or lower
   2. designating or of visibility along the ground regarded as within the limit of a few feet
5. Linguis. designating a hypothetical inflectional form the plural of deer is said to be formed by the addition of a zero allomorph of the plural morpheme

transitive verb zeroed -·roed, zeroing -·ro·ing