approximation

approximation is a Noun

Definition:

[1] The act of approximating; a drawing, advancing or being near; approach; also, the result of approximating. The largest capacity and the most noble dispositions are but an approximation to the proper standard and true symmetry of human nature. I. Taylor.

[2] An approach to a correct estimate, calculation, or conception, or to a given quantity, quality, etc.

[3] A continual approach or coming nearer to a result; as, to solve an equation by approximation.

[4] A value that is nearly but not exactly correct.