zero

1. (informal, uncountable) Nothing, or none.Examples: "The shipment was lost, so they had zero in stock."; "He knows zero about humour."; "In the end, all of our hard work amounted to zero."informaluncountable

2. (mathematics) A value of the independent variables of a function, for which the function is equal to zero.Examples: "The zeroes of a polynomial are its roots by the fundamental theorem of algebra."; "The derivative of a continuous, differentiable function that twice crosses the axis must have a zero."; "The nontrivial zeros of the Riemann zeta function may all lie on the critical line."countableuncountable

3. (mathematics, algebra) The additive identity element of a monoid or greater algebraic structure, particularly a group or ring.Examples: "Since a commutative zero is the inverse of any additive identity, it must be unique when it exists."; "The zero (of a ring or field) has the property that the product of the zero with any element yields the zero."; "The quotient ring over a maximal ideal is a field with a single zero element."Synonyms: additive identitycountableuncountable

4. (slang) A person of little or no importance.Examples: "They rudely treated him like a zero."Synonyms: cipher, nobody, nonentitycountableslanguncountable

5. (military, usually capitalized) A Mitsubishi A6M Zero, a long range fighter aircraft operated by the Imperial Japanese Navy Air Service from 1940 to 1945.Examples: "The visit to Townsville was filled with nostalgia for me. I remembered very well staying there on June 8, 1942. I shared a room with a brave and friendly officer, Colonel Francis Stevens. Early the next morning we flew to Port Moresby in New Guinea, and from there we took off in separate planes. Colonel Stevens never returned from that flight; his plane was shot down by a Japanese Zero."capitalizedcountableuncountableusually

6. (finance) A security which has a zero coupon (paying no periodic interest).Examples: "The takeovers were financed by issuing zeroes."countableuncountable