variance

Meanings

1. The act of varying or the state of being variable.
2. A difference between what is expected and what is observed; deviation.
3. The state of differing or being in conflict.
4. An official permit to do something that is ordinarily forbidden by regulations.
5. A discrepancy between two legal documents.
6. A departure from a cause of action originally in a complaint.
7. The second central moment in probability; the square of the standard deviation.
8. The number of degrees of freedom in a system.
9. Covariance and contravariance generally.

Etymology

From Middle English variance, variaunce, equivalent to vary + -ance, from Old French variance or directly from Anglo-Latin variaunce, veriaunce, wariaunce; all from Latin variantia.