›[C or U]the number 0: They agreed to cut tariffs on 4,000 categories of goods to between zero and 5% by 2013.
›[U]nothing at all, or the lowest possible amount: The intent of sustainable business development is to drive outputs of hazardous waste to zero.zero cost/growthThe economic reform packages stirred the economy from zero growth.
›[U]MEASURESon a set of numbers for comparing temperature in degrees Celsius, the level of temperature at which water freezes: The temperature dropped to ten degrees below zero.