A cipher; nothing; naught.
- The numerical symbol 0; a cipher.
- Mathematics The identity element for addition.
- Mathematics A cardinal number indicating the absence of any or all units under consideration.
- Mathematics An ordinal number indicating an initial point or origin.
- Mathematics An argument at which the value of a function vanishes.
- The temperature indicated by the numeral 0 on a thermometer.
- A sight setting that enables a firearm to shoot on target.
- Informal One having no influence or importance; a nonentity: a manager who was a total zero.
- The lowest point: His prospects were approaching zero.
- A zero-coupon bond.
- Informal Nothing; nil: Today I accomplished zero.
- Of, relating to, or being zero.
- Having no measurable or otherwise determinable value.
- Informal Absent, inoperative, or irrelevant in specified circumstances: "The town has . . . practically no opportunities for amusement, zero culture” ( Robert M. Adams).
- Meteorology Designating a ceiling not more than 16 meters (52 feet) high.
- Meteorology Limited in horizontal visibility to no more than 55 meters (180 feet).
- Linguistics Of or relating to a morpheme that is expected by an established, regular paradigm but has no spoken or written form. Moose has a zero plural; that is, its plural is moose.
- To adjust (an instrument or a device) to zero value.
- zero in To aim or concentrate firepower on an exact target location.
- zero in To adjust the aim or sight of by repeated firings.
- zero in To converge intently; close in: The children zeroed in on the display of toys in the store window.
- zero out To eliminate (a budget or budget item) by cutting off funding.
- zero out To reduce to zero.