noun

1. ZERO, the sight setting that will cause a projectile to hit the center of the target with no wind blowing
2. ZERO, the point on a scale from which positive or negative numerical quantities can be measured
3. ZERO, a quantity of no importance
4. ZERO, a mathematical element that when added to another number yields the same number
5. ZERO, the number 0
6. ZERO, the temperature shown by the zero mark on a thermometer
7. ZERO, nothing at all

verb

1. ZERO, adjust (as by firing under test conditions) the zero of (a gun)
2. ZERO, adjust (an instrument or device) to zero value
3. ZERO, to set (a measuring device, such as a scale) so that it reads 0

adjective

1. ZERO, indicating the absence of any or all units under consideration
2. ZERO, indicating an initial point or origin
3. ZERO, having no measurable or otherwise determinable value

adjective

1. ZERO, of or relating to the null set (a set with no members)

1. Two minus two equals zero.
2. It's supposed to fall below zero tonight.
3. The temperature is 10° above zero.