n (mathematics) A value of the independent variables of a function, for which the function is equal to zero.
n (mathematics|algebra) The additive identity element of a monoid or greater algebraic structure, particularly a group or ring.
n (military) A (w|Mitsubishi A6M Zero), a long range fighter aircraft operated by the Japanese Navy Air Service from 1940 to 1945.
v (transitive|computing) To change a memory location or range to values of zero; to set a variable in a computer program to zero.