1. A leading or drawing off of water from a stream or source.
2. The act of receiving anything from a source; the act of procuring an effect from a cause, means, or condition, as profits from capital, conclusions or opinions from evidence. As touching traditional communication, . . . I do not doubt but many of those truths have had the help of that derivation. (Sir M. Hale)
3. The act of tracing origin or descent, as in grammar or genealogy; as, the derivation of a word from an aryan root.
4. The state or method of being derived; the relation of origin when established or asserted.
5. That from which a thing is derived.
6. That which is derived; a derivative; a deduction. From the Euphrates into an artificial derivation of that river. (Gibbon)
7. (Science: mathematics) The operation of deducing one function from another according to some fixed law, called the law of derivation, as the of differentiation or of integration.
8. (Science: medicine) a drawing of humors or fluids from one part of the body to another, to relieve or lessen a morbid process.
Origin: L. Derivatio: cf. F. Derivation. See derive.