general level or average: Two cars per family is the norm in most suburban communities.

Education.

a designated standard of average performance of people of a given age, background, etc.

a standard based on the past average performance of a given individual.

Mathematics.

a real-valued, nonnegative function whose domain is a vector space, with properties such that the function of a vector is zero only when the vector is zero, the function of a scalar times a vector is equal to the absolute value of the scalar times the function of the vector, and the function of the sum of two vectors is less than or equal to the sum of the functional values of each vector. The norm of a real number is its absolute value.

the greatest difference between two successive points of a given partition.

Origin of norm

First recorded in 1815–25,norm is from the Latin word norma carpenter's square, rule, pattern

"standard, pattern, model," 1821, from French norme, from Latin norma "carpenter's square, rule, pattern," of unknown origin. Klein suggests a borrowing (via Etruscan) of Greek gnomon "carpenter's square." The Latin form of the word, norma, was used in English in the sense of "carpenter's square" from 1670s.