(geography) Earth’s equator.

(programming) A statement in assembly language that defines a symbol having a particular value.

(transitive) To consider equal or equivalent. / (transitive, mathematics) To set as equal.

plural of equation

Of, pertaining to, or constructed using equations

The quality of being equatable.

(exobiology) A formula for calculating the probability of civilizations existing elsewhere in the Milky Way galaxy and of their ability to communicate with Earth.

plural of differential equation

(chemistry) Either of two equations that describe each half of a redox reaction

(physics) A relativistic wave equation that describes an electron (and similar particles); it predicted the existence of antiparticles