(physics, quantum mechanics) The lowest possible energy of a given quantum mechanical system.

(game theory) A game (or a similar political or economic system) in which the gains of some players must equal the losses of others.

(finance) A bond (e.g., corporate debenture or government debt) that has no coupon (i.e., pays no interest), during the life of the issue. Such a bond is initially sold at a discount to its face value. The rate of return to the holder is derived from the gradual appreciation as the security moves toward maturity.

(military) A technique in which the first motion of the missile or aircraft removes it from the launcher. Normally, such a launch occurs before the missile fuel or aircraft engine is fired.

A vehicle that produces only carbon dioxide and water as its emissions and so does not pollute the air.

(cryptography) An interactive method for one party to prove to another that a (usually mathematical) statement is true, without revealing anything other than the veracity of the statement.

(surveying) An optimal network design within a computer. It involves choosing an optimal reference system and revolving it around a certain real number.

plural of zero-point energy

(mathematics) The fact that, in some circumstances, the probability of an event can only be zero or one and not any intermediate value.

(UK) A contract of employment that creates an on-call arrangement in which the employee agrees to be available for work as and when required, without any particular number of hours or times of work being specified or guaranteed.